The need for small-size and on-chip integrable and inexpensive detecting systems, including for biological and medical applications, have prompted the development of easily processable organic field-effect transistor (OFET)- and light-emitting diode (OLED)-based sensors integrated with organic or hybrid photodetectors. The growing activity and progress in flexible, organic, printable, and hybrid electronics enable the development of skin display electronic, as well as flexible wearable and implantable sensors. OLEDs and OLED arrays in optogenetics for potential implantable optical-neural interfaces, as well as modulation of neuronal networks activity is a biophotonics platform of growing interest. A better understanding of the organic/living tissue interface, which will lead to the design of better biosensing and biophotonics concepts, remains a challenge.

Overall fast and simultaneous detection of multiple analytes utilizing micro/nano array systems continues to open a plethora of novel applications in key areas such as clinical analysis, environment monitoring, food and beverage safety, and homeland security. Solution or easily processable two-dimensional metal oxides, carbon-based, and hybrid organic/inorganic 2D and 3D materials have proven useful as active layers in chemical and biological transducers. Novel technological approaches that allow the integration of functional bio-receptors into device structures are also critically important to endow such devices with recognition capabilities. Continued research and development efforts are needed, including with newly emerging technologies on hybrid memory devices and logic elements to further improve sensors' performance level and low-cost manufacturability.

This conference will focus on progress in chemical, biological, medical, and physical sensors and actuators, including image sensors and flexible/stretchable e-skin, and large-scale devices from carbon-based, solution processable metal-oxides, and hybrid organic/inorganic materials. Devices such as organic-, quantum dot, 2D semiconductor, and perovskite-based photodetectors and organic bioelectronic devices, including neural interfaces, optogenetics, diagnostics, drug delivery devices, food analysis, water sensing, and tissue engineering concepts using optical and electrical activation will be discussed.

The conference will focus also on the science and technology of next generation memory and logic devices based on organic, hybrid organic/inorganic, and inorganic materials, which are predominately fabricated by printing technologies. It will span a broad spectrum from fundamental science related to novel materials development and processing to addressing issues related to organic and inorganic surfaces and interfaces, to device fabrication, system applications, and integration using novel printing methods.

Contributions related (but not limited) to the following topics are solicited:
Highlight: ;
In progress – view active session
Conference 11810

Organic and Hybrid Sensors and Bioelectronics XIV

In person: 1 August 2021 | Conv. Ctr. Room 5B
On demand now
View Session ∨
  • 1: Organic Bioelectronics
  • 2: Materials for Sensors and Bioelectronics
  • 3: Devices and Sensor Elements
  • 4: Neuromorphic Devices and Applications
  • Sunday Evening Plenary Session
  • Organic Photonics + Electronics Plenary Networking Event
  • Organic Photonics + Electronics Plenary Session I
  • Tuesday Smoothies and Cool Jazz Scene
  • Organic Photonics + Electronics Plenary Session II
  • Poster Session
Session 1: Organic Bioelectronics
In person: 1 August 2021 • 1:30 PM - 2:10 PM PDT | On Demand
Session Chairs: Ruth Shinar, Iowa State Univ. of Science and Technology (United States), Ioannis Kymissis, Columbia Univ. (United States)
11810-1
CANCELED: In-vivo manufactured organic bioelectronics (Keynote Presentation)
In person: 1 August 2021 • 1:30 PM - 2:10 PM PDT | On Demand
Show Abstract + Hide Abstract
In conducting polymers, transport and polarisation of electronic charges and ions are tightly coupled. This feature enables an array of organic electrochemical devices, such as OECTs, electrophoretic delivery devices, sensors and more, which all have been applied to biology and in medicine; Organic Bioelectronics. Organic bioelectronics are traditionally manufactured on 2D surfaces using traditional photolithography and printing tools. In order to advance and achieve a more seamless integration of bioelectronic devices with biological systems, our laboratory have explored in vivo-manufacturing protocols, in which organic electro-active materials self-organise and self-polymerise within and along biological systems. Further, n-type conjugated polymers will be presented along with several key-demonstrations in part targeting complementary n- and p-type device and circuit systems.
11810-2
Author(s): Sahika Inal, King Abdullah Univ. of Science and Technology (Saudi Arabia)
On demand
Session 2: Materials for Sensors and Bioelectronics
In person / Livestream: 1 August 2021 • 2:10 PM - 3:00 PM PDT | Conv. Ctr. Room 5B
Session Chairs: Ruth Shinar, Iowa State Univ. of Science and Technology (United States), Ioannis Kymissis, Columbia Univ. (United States)
11810-7
Author(s): Alon Gorodetsky, Preeta Pratakshya, Univ. of California, Irvine (United States)
On demand | Presented Live 1 August 2021
Show Abstract + Hide Abstract
Cephalopods (e.g., squids, octopuses, and cuttlefish) have captivated the imagination of both the general public and scientists alike due to their sophisticated nervous systems, complex behavioral patterns, and visually stunning camouflage displays. Given their unique capabilities and characteristics, it is not surprising that these marine invertebrates have emerged as exciting models for novel adaptive optical and photonic materials. Within this context, our laboratory has developed various cephalopod-derived and cephalopod-inspired systems with dynamic functionalities within the visible and infrared regions of the electromagnetic spectrum. Our findings hold implications for next-generation adaptive camouflage devices and biomedical imaging technologies.
11810-10
Author(s): Hung Phan, Fulbright Univ. Vietnam (Vietnam); Thomas Kelly, Loyola Marymount Univ. (United States); Hieu Huynh, An Nguyen, Fulbright Univ. Vietnam (Vietnam); Andriy Zhugayevych, Skolkovo Institute of Science and Technology (Russian Federation); Sergei Tretiak, Los Alamos National Lab. (United States); Thuc-Quyen Nguyen, Univ. of California, Santa Barbara (United States); Emily Jarvis, Loyola Marymount Univ. (United States)
On demand | Presented Live 1 August 2021
Show Abstract + Hide Abstract
The change in optical properties of an organic semiconductors upon forming adducts with inexpensive small molecules is attractive in organic electronics. We focus on the adducts of conjugated molecules and Lewis acids (CM-LA), formed by the partial electron transfer from a CM containing a Lewis basic site to an LA such as BF3 and B(C6F5)3. The resulting adducts showed intriguing optoelectronic properties, including a red-shift in optical transitions and an increase in charge carrier density compared to the parent conjugated molecules. In this work, we combine electronic structure modelling and machine learning (ML) to quantify, analyze and predict the electron transfers and red-shifts of the adducts from chemical structures. For ML model, we utilize DFT-calculated electron transfers and redshifts and molecular descriptors readily calculated from molecular structures. Our work can help researchers in other fields in predicting fundamental properties from molecular structures.
11810-6
Author(s): Nurit Ashkenasy, Ben-Gurion Univ. of the Negev (Israel)
On demand
Show Abstract + Hide Abstract
The talk describes a bio-inspired approach to design and prepare proton conducting materials based on self-assembling short protein sequences (peptides). The effect of amino-acid side-chain and backbone conformation on proton conductivity of the peptide fibrils will be discussed. We will show that the rational design of peptides can lead to fabrication of novel type of environmentally friendly, high performance, self-assembling, proton conducting materials.
11810-8
Author(s): Herdeline Ann Ardoña, Univ. of California, Irvine (United States)
On demand
11810-9
Author(s): Nadav Amdursky, Technion-Israel Institute of Technology (Israel)
On demand
Show Abstract + Hide Abstract
Nature uses proteins for a variety of functions, and among all others, their ability to form high-hierarchical structures as well as to mediate charges. We are inspired by these functions of proteins in nature and utilize proteins for the formation of large-scale conductive materials. We report here on a new family of conductive biopolymers using only sustainable and abundant proteins. We show that our new biopolymers have superior mechanical properties and ionic conductivity, which is due to their high water uptake and the presence of oxo-amino-acids. We further show that our biopolymers can be easily functionalized in different ways, thus enhancing their ionic conductivity, enabling electron conduction, and introducing optoelectronic properties. We currently use our polymers for making new biosensors. These polymers are environmentally friendly, biodegradable, biocompatible, and low-cost, and we foresee their integration in numerous applications from biomedical to energy applications
11810-13
Author(s): Gianluca M. Farinola, Gabriella Buscemi, Rossella Labarile, Roberta Ragni, Univ. degli Studi di Bari Aldo Moro (Italy); Francesco Milano, Istituto di Scienze delle Produzioni Alimentari (Italy); Danilo Vona, Univ. degli Studi di Bari Aldo Moro (Italy); Massimo Trotta, Istituto per i Processi Chimico Fisici (Italy)
On demand
Show Abstract + Hide Abstract
Photosynthetic microorganisms and their Reaction Center (RC) photoenzymes can be used as active materials for bio-optoelectronic applications. Here we report approaches to interface RC molecules extracted from Rhodobacter sphaeroides with electrodes aiming to integrate the RC in electronic and electrochemical devices. Covalent binding with molecular semiconductors or supramolecular organization based on selective interactions have been explored. Alternatively, entrapment of the RC in biocompatible polymers is a convenient approach. These soft structures include polydopamine-based films or polydopamine/ethylenediamine nanoparticles capable of confining and protecting the RC, while improving RC-electrode charge transfer. We also describe the use of these polymers to address living photosynthetic bacterial cells on electrodes.
11810-14
Author(s): Darwin Patricio Castillo Malla, Aramis Sánchez, Jandry González, Univ. Técnica Particular de Loja (Ecuador); Cristian Chamba, Universidad Técnica Particular de Loja (Ecuador); Vasudevan Lakshminarayanan, Univ. of Waterloo (Canada)
On demand
Show Abstract + Hide Abstract
The ultraviolet (UV) index is an international standard measurement of the strength of solar ultraviolet radiation on the earth's surface at a particular place and time. According to the World Health Organization (WHO), the maximum UV index score for humans is 11 points. Solar radiation with a high UV index can produce damage to the skin and eye (photoaging and photokeratitis). The levels of UV radiation are commonly detected using silicon-based optoelectronic sensors, which can be expensive. Here we propose a way to measure the UV index using natural organic pigments which fluoresce when exposed to UV radiation. Curcuma longa fluoresces in the range of 500 to 680 nm when exposed to UV radiation. The sensor measures the variation in fluorescence intensity using a light-dependent resistor to determine radiation levels and correlate them with the UV index. The sensor has been tested in Loja, Ecuador which UV levels can reach up to 20.0.
Session 3: Devices and Sensor Elements
In person / Livestream: 1 August 2021 • 3:30 PM - 5:00 PM PDT | Conv. Ctr. Room 5B
Session Chairs: Ruth Shinar, Iowa State Univ. of Science and Technology (United States), Ioannis Kymissis, Columbia Univ. (United States)
11810-18
Author(s): Do Young Kim, Vishal Yeddu, Gijun Seo, Oklahoma State Univ. (United States)
On demand | Presented Live 1 August 2021
Show Abstract + Hide Abstract
Halide perovskites are very attractive for solution-processed visible and near-IR sensing applications due to their intrinsic advantages such as excellent photosensitivity, bandgap tunability, broadband sensitivity, high charge transport capability, and solution-processability. Unlike Pb-based perovskites, which cannot be tuned to below 1.48 eV, Pb-Sn mixed halide perovskites exhibit low bandgaps of 1.2-1.3 eV. Due to the low bandgap, these Pb-Sn mixed halide perovskite can absorb light till 1000nm making them a viable alternative to Silicon as the visible and near-IR broadband photodetectors. However, the low-bandgap nature of Pb-Sn mixed perovskites also causes large levels of electron and hole injection from anode and cathode, thus leading to high dark current. To mitigate the issue of charge injection, therefore, it is important to have an electron blocking layer (EBL) and a hole blocking layer (HBL) inserted between the electrodes and the Pb-Sn mixed perovskite photodetectors.
11810-20
Author(s): Mohammad Shakhawat Hossain, Arash Takshi, Univ. of South Florida (United States)
On demand | Presented Live 1 August 2021
Show Abstract + Hide Abstract
In this work, a comparative study of methylammonium lead iodide (MAPbI3) perovskite's selectivity towards acetone, ethanol, isopropanol, and methanol has been presented. For the comparative study, two different geometrical orientations have been considered: capillary microchannel design, and thin-film design. Samples of both designs have been tested under dark and illuminated conditions and the trend in the change of conductivity of the perovskite is observed. Preliminary study suggests that under illuminated condition, thin-film design exhibits higher selectivity toward ethanol, isopropanol, and methanol, compared to the capillary design., while, under dark condition, capillary design exhibited higher selectivity toward acetone, ethanol, and methanol.
11810-26
Author(s): Zachary A. Lamport, Columbia Univ. (United States); Marco R. Cavallari, Univ. Federal da Integração Latino-americana (Brazil); Michael J. Bardash, Radiation Detection Solutions (United States); Ioannis Kymissis, Columbia Univ. (United States)
On demand | Presented Live 1 August 2021
Show Abstract + Hide Abstract
Here, we report on an all-organic solid-state radiation dosimeter patterned onto a plastic substrate that allows for real-time measurements communicated over WiFi. The “sense” area and the conductive traces are made using low-conductivity PEDOT:PSS, and measurements are read out by a low-current op-amp. As the detector is subjected to radiation, the ionized air, substrate, and sense area cause a charge accumulation which is then read out as a voltage from the op-amp. OFETs on either side of the sense area allow for the charge to be cleared, allowing for accurate dose measurement without saturation. Additionally, the inclusion of a PEDOT:PSS ground plane as the first layer on the PEN substrate helps to shield the sensor itself from extraneous static. For X-rays, the limit of detection is approximately 5 mRad/min, and for gamma rays the limit is approximately 5 mRad/hr. Through appropriate control of the clearing OFETs, the device is quickly reset to allow for a continuous measurement.
11810-27
Author(s): Andrew Zeidell, National Strategic Research Institute (United States); Tong Ren, Wake Forest Univ. School of Medicine (United States); David S. Filston, Hamna Haneef, Wake Forest Univ. (United States); Emma Holland, Univ. of Kentucky Ctr. for Applied Energy Research (United States); Daniel J. Bourland, Wake Forest Univ. School of Medicine (United States); John E. Anthony, Univ. of Kentucky Ctr. for Applied Energy Research (United States); Oana D. Jurchescu, Wake Forest Univ. (United States)
On demand | Presented Live 1 August 2021
Show Abstract + Hide Abstract
Controlling the amount of radiation that a cancer patient receives during treatment is critical to ensure the intended treatment outcome. In this work we use small molecule organic semiconductor devices as radiation sensors/dosimeters which have an effective Z close to that of human tissue. Solution processing provides excellent opportunities for scalability on flexible substrates, allowing them to conform to skin and clothing, and enabling dose measurement at the point of entry to the human body. Previous work using organic field-effect transistors (OFETs) for radiation detection has focused on radiation doses much greater than received by patients during cancer diagnostic imaging and treatment, while this work focuses on the response of OFET-based sensors at low doses relevant to cancer treatment. A systematic change in the threshold voltage of the FETs was observed with cumulative dose. Our results demonstrate that OFETs may be used in dosimetry applications for oncology.
11810-15
Author(s): Ifor D. W. Samuel, Univ. of St. Andrews (United Kingdom)
On demand
Show Abstract + Hide Abstract
OLEDs have many attractive features as light sources for applications in biology and medicine. Photodynamic therapy (PDT) involves the use of light, a photosensitizer and oxygen to kill target cells which can be cancer, bacteria, parasites or fungi. There is a growing realisation that PDT may not only be useful for treating cancers, but also for the growing problem of antimicrobial resistance. This talk will describe the development of OLEDs for PDT, taking account of the particular needs of this application in terms of size, wavelength, light output, uniformity and lifetime. It will show work towards achieving high uniformity at high light output (~10 mW/cm2) over a substantial area and examples of antimicrobial applications.
11810-16
Author(s): Jinsong Huang, The Univ. of North Carolina at Chapel Hill (United States)
On demand
Show Abstract + Hide Abstract
Hybrid perovskite materials are attractive for detection of X-ray and gamma-ray in both direct and indirect ways. The high stopping power of perovskites as well as excellent charge transport properties enables direct detection of single photon gamma ray in photon counting mode. The strong absorption of UV-vis light by most hybrid perovskites also enable very sensitive photodetectors which can count the emitted photons from scintillators under radiation. In addition, many perovskite compositions are also explored for scintillator applications. I am going to review the progress made at UNC on these three main research directions.
11810-17
Author(s): Maheshani Prabodhi Alwis Nanayakkara, Mateus Gallucci Masteghin, Univ. of Surrey (United Kingdom); Laura Basiricò, Ilaria Fratelli, Andrea Ciavatti, Beatrice Fraboni, Univ. degli Studi di Bologna (Italy); Imalka Jayawardena, Ravi P. Silva, Univ. of Surrey (United Kingdom)
On demand
Show Abstract + Hide Abstract
There is a growing need for curved X-ray detectors for use in medical, industrial, and security applications for imaging of complex shapes. Fabrication of such curved X-ray detectors require materials that can sustain mechanical stresses. Organic-inorganic hybrid X-ray detectors consisting of high atomic number nanoparticles in an organic bulk heterojunction matrix has the potential to enable this. However organic semiconductors can crystallise depending on their molecular weight, thereby restricting deformation. In this study, we evaluate the influence of the molecular weight of organic semiconductors on the inherent strain in such hybrid detectors. We demonstrate that a careful selection of molecular weight and substrate thickness is a necessity to enable curved detectors. Based on optimised combinations, we show that such detectors can be curved to a very small radius of curvatures approaching 1 mm which ensures compatibility for applications in a multitude of fields.
11810-19
Author(s): Takafumi Uemura, Tsuyoshi Sekitani, Osaka Univ. (Japan), PhotoBIO-OIL, National Institute of Advanced Industrial Science and Technology (Japan)
On demand
Show Abstract + Hide Abstract
In this presentation, we report an ultraflexible magnetic sensor matrix system comprising a 2 × 4 array of magnetoresistance sensors, a bootstrap organic shift register driving the matrix, and organic voltage amplifiers integrated within a 3-µm-thick polymer substrate. The system demonstrates high magnetic sensitivity owing to the use of organic amplifiers. Moreover, the shift register enabled real-time mapping of 2D magnetic field distribution. These ultraflexible magnetic sensor systems integrated with organic multifunctional circuits are suitable for use in position control systems used in applications such as soft robots, wearable electronics, and smart textiles.
11810-22
Author(s): Rahul Eswar, C. Harrison Brodie, Christopher M. Collier, Univ. of Guelph (Canada)
On demand
Show Abstract + Hide Abstract
Detection of antibiotic residues in milk is paramount to the dairy industry as the concentration of this contaminant is strictly regulated to protect human health. The industry standard of low-interval off-site laboratory screening is insufficient for detection of non-compliant milk on the farm site. Microfluidic technologies are positioned to address this issue by leveraging on-site high-interval screening of antibiotics in milk via integration of fluorescence spectroscopy. The development of a digital microfluidic platform is presented in terms of scalability and automation. Characterization of actuation performance is performed for various system configurations, dielectric layers, with both water and milk microdroplets.
11810-23
Author(s): Yueh-Cheng Lin, Chi-Hsien Cheng, Yu-Chueh Hung, National Tsing Hua Univ. (Taiwan)
On demand
Show Abstract + Hide Abstract
In recent years, optoelectronic devices are implemented based on natural DNA with enhanced performance and efficiency. In this study, we present stimulus pulse-dependent responses in natural DNA biopolymer devices. The device consists of a simple sandwich structure and the resistivity can be manipulated with respect to voltage operation. We characterize the stimulus pulse-dependent responses, where the synaptic plasticity will be presented. To further explore dynamics of resistive states, the effect of incorporating a photo-responsive material on the light-triggered electrical characteristics will be discussed. Our results reveal natural DNA biopolymer shows great promise for the development of synaptic devices for neuromorphic circuitry.
11810-25
Author(s): Steffen Rühl, Max Heyl, Fabian Gärisch, Sylke Blumstengel, Giovanni Ligorio, Emil J. W. List-Kratochvil, Humboldt-Univ. zu Berlin (Germany)
On demand
Show Abstract + Hide Abstract
Most electrical sensor and biosensors elements require reliable transducing elements to convert small potential changes into easy to read out current signals. Offering inherent signal magnification and being operable in many relevant environments field-effect transistors (FETs) are the element of choice in may cases. In particular using electrolyte gating numerus sensors and biosensors have been realized in aqueous environments. Over the past yeas electrolyte gated FETs have been fabricated using a variety of semiconducting materials including graphene, ZnO as well as conjugated molecules and polymers. In particular using conducting polymers top performing devices have been achieved. Here we present an approach to use a transition metal dichalcogenide (TMDCs) based monolayer device. Using MoS2 monolayers we show that such electrolyte gated devices may be regarded as very promising future transducing elements for sensor and biosensor applications.
Session 4: Neuromorphic Devices and Applications
11810-28
Author(s): Paschalis Gkoupidenis, Max-Planck-Institut für Polymerforschung (Germany)
On demand
Show Abstract + Hide Abstract
The seamless integration of electronics with biology requires new bio-inspired approaches that, analogously to nature, rely on the presence of electrolytes for signal multiplexing. On the contrary, conventional multiplexing schemes mostly rely on electronic carriers and require peripheral circuitry for their implementation, which imposes limitations toward their adoption in bio-applications. Here we show an iontronic multiplexer based on spatiotemporal dynamics of organic electrochemical transistors (OECTs), with an electrolyte as the shared medium of communication. The iontronic system discriminates locally random-access events with no need of peripheral circuitry, thus deceasing significantly the integration complexity. The form factors of OETCs, open new avenues for unconventional multiplexing in the emerging fields of bioelectronics and neuromorphic sensors. Examples of organic neuromorphic electronics for local learning in applications with energy restrictions are also showcased.
11810-30
Author(s): Sudhanva Vasishta, Xiao Wang, Calla McCulley, The Univ. of Texas at Austin (United States); Raghunandan K.R., Silicon Labs. (United States); Viswanathan T.R., Ananth Dodabalapur, The Univ. of Texas at Austin (United States)
On demand
Show Abstract + Hide Abstract
Polymer, organic, and graphene based chemical sensors have shown excellent performance as chemical sensors. They can be chemically modified with receptor groups to provide additional sensitivity and selectivity. We propose and will demonstrate a three-synapse neuromorphic circuit for chemical sensing and olfactory pattern recognition. The circuit is implemented with 180 nm silicon technology and the sensing synapses can be incorporated in a back-end-of-the-line process on the silicon chip or be fabricated separately and electrically connected to the rest of the circuit. Our neuromorphic circuit is designed to be suited for analyzing mixtures of two analytes. We will present both simulation results and experimental data. The active sensing material for the sensing synapses can include conducting polymers such as PEDOT, monolayer graphene, reduced graphene oxide, copper phthalocyanine, as well as other materials.
Sunday Evening Plenary Session
In person / Livestream: 1 August 2021 • 6:00 PM - 7:35 PM PDT | Conv. Ctr. Room 6A
6:00 PM: Welcome and Opening Remarks:
John Greivenkamp, 2021 Immediate Past President, Wyant College of Optical Sciences (United States)
11819-501
Author(s): Paul L. Hertz, NASA Headquarters (United States)
In person / Livestream: 1 August 2021 • 6:00 PM - 6:30 PM PDT | Conv. Ctr. Room 6A
Show Abstract + Hide Abstract
NASA seeks to discover how the universe works, explore how the universe began and developed into its present form, and search for Earth-like planets. The core of NASA’s astrophysics program is a portfolio of space missions ranging from CubeSats and PI-led Explorers to Great Observatories like the Hubble Space Telescope. The space missions are enabled by extensive programs in supporting research and technology development. The 2020 Decadal Survey in Astronomy and Astrophysics will identify new science priorities for NASA. This talk will summarizes NASA’s astrophysics program and discuss possible visions for the future of NASA astrophysics.
11821-501
Author(s): Shouleh Nikzad, Jet Propulsion Lab. (United States)
On demand | Presented Live 1 August 2021
Show Abstract + Hide Abstract
Silicon imagers are ubiquitous in the consumer landscape. With nanoscale engineering, they can become high performance scientific imagers with high sensitivity and extended spectral range response, enabling discoveries and capabilities in space exploration. This allows an opportunity to leverage the enormous investment in these imagers. In this plenary talk, Dr. Shouleh Nikzad will describe how surface engineering enables high performance in detectors, filters, and coating technologies which in turn could enable discoveries in future space missions ranging from CubeSats to flagship. She will also discuss the synergistic way these technologies can be used for terrestrial applications and in particular medical applications.
Organic Photonics + Electronics Plenary Networking Event
In person: 3 August 2021 • 8:00 AM - 8:30 AM PDT | Conv. Ctr. Room 6A
Join us for a short reception prior to the plenary session for refreshments and networking.
Organic Photonics + Electronics Plenary Session I
In person / Livestream: 3 August 2021 • 8:30 AM - 10:00 AM PDT | Conv. Ctr. Room 6A
Session Chair: Zakya H. Kafafi, Lehigh Univ. (United States)

8:30 AM: Welcome and Opening Remarks
11808-501
Author(s): Richard H. C. Friend, Univ. of Cambridge (United Kingdom)
In person / Livestream: 3 August 2021 • 8:35 AM - 9:15 AM PDT | Conv. Ctr. Room 6A
Show Abstract + Hide Abstract
Pi-conjugated organic molecules and polymers now provide a set of well-performing semiconductors that support devices, including light-emitting diodes (LEDs) as used in smart-phone displays and lighting, field-effect transistors (FETs) and photovoltaic diodes (PVs). These are attractive materials to manufacture, particularly for these large-area applications, but, as I will explore in this talk, their electronic properties are very different from standard semiconductors such as silicon. Firstly, electronic overlap between adjacent molecules is relatively poor, and this often drives localization of electronic states. Secondly, dielectric screening is weak so that Coulomb interactions between charges and spin exchange energies are large. Management of transport and of excited state spin is fundamental for efficient LED and solar cells operation. I will discuss some of our recent work in Cambridge. I will discuss the use of spin ½ ‘radical’ semiconductors where we can light emission to the spin doublet excited state that avoid non-radiative spin triplet states. In contrast, I will present recent results that show triplet formation still limits the performance of the better-performing organic solar cells based on non-fullerene acceptors such as ‘Y6’.
11809-502
Author(s): Jean-Luc Brédas, The Univ. of Arizona (United States)
On demand | Presented Live 3 August 2021
Show Abstract + Hide Abstract
Recent advances in organic solar cells are based on non-fullerene acceptors (NFAs) and come with reduced non-radiative voltage losses (ΔVnr). In this presentation [see Chen et al., Nature Energy, DOI: 10.1038/s41560-021-00843-4], we show that, by contrast to the energy-gap-law dependence observed in conventional donor:fullerene blends, the ΔVnr values in state-of-the-art donor:NFA organic solar cells show no correlation with the energies of charge-transfer electronic states at donor:acceptor interfaces. By combining temperature-dependent electroluminescence experiments and dynamic vibronic simulations, a unified description of ΔVnr is reached for both fullerene- and NFA-based devices. The critical role that the thermal population of local exciton states plays in low-ΔVnr systems is also highlighted. Another interesting finding is that it is the photoluminescence yield of the pristine materials that defines the lower limit of ΔVnr.
Tuesday Smoothies and Cool Jazz Scene
In person: 3 August 2021 • 3:00 PM - 4:00 PM PDT | Conv. Ctr. Sails Pavilion, Exhibition Hall Coffee Area
Cool off with a smoothie while you network with other conference goers and chill with a smooth Jazz trio.
Organic Photonics + Electronics Plenary Session II
In person / Livestream: 3 August 2021 • 4:00 PM - 5:30 PM PDT | Conv. Ctr. Room 6A
Session Chair: Zakya H. Kafafi, Lehigh Univ. (United States)

4:00 PM: Welcome and Opening Remarks
11809-503
Perovskite Solar Cells (Plenary Presentation)
Author(s): Anita Ho-Baillie, The Univ. of Sydney (Australia)
On demand | Presented Live 3 August 2021
Show Abstract + Hide Abstract
In this talk, I will give a short overview of perovskite solar cells with regards to their opportunities and challenges. Opportunities for performance improvement will be highlighted. Challenges regarding durability will be discussed touching on our work on understanding intrinsic stability of perovskites and meta-stability of perovskite solar cells and strategies for boosting perovskite solar cells’ durability against thermal extremes and humidity. Our perovskite solar cells were the first to exceed the strict requirements of International Electrotechnical Commission standards for thermal cycling damp heat and humidity freeze. Such a major breakthrough represents an important step towards commercial viability.
11808-504
Author(s): Franky So, North Carolina State Univ. (United States)
On demand | Presented Live 3 August 2021
Show Abstract + Hide Abstract
OLEDs are thin-film devices consisting of multilayers of organic thin films sandwiched between a metal and an ITO electrodes. Because of the different refractive indices of the layers in the thin film stack, different optical modes are trapped in the device. In this talk, we will first discuss the physics of these optical modes and describe techniques to characterize them. We will then describe how to use various photonic structures to maximize the light output and manipulate these optical modes to control the polarization as well as directionality to achieve beam shaping.
Poster Session
In person: 3 August 2021 • 5:30 PM - 7:00 PM PDT | Conv. Ctr. Sails Pavilion, City Trellis Entrance
11810-31
Author(s): Shichen Yin, Franky So, Shuo Ding, Liping Zhu, Qi Dong, Carr Hoi Yi Ho, North Carolina State Univ. (United States)
On demand | Presented Live 3 August 2021
Show Abstract + Hide Abstract
Narrow bandgap lead sulfide (PbS) quantum dots (QDs) are solution-processed materials used for optoelectronic applications in the short-wavelength infrared (SWIR) range (1400 - 3000 nm). The PbS QDs based photodetector has achieved comparable detectivity with current commercial SWIR sensors. However, there are still obstacles towards commercialization in commonly used layer by layer (LbL) deposition, such as high material consumption and low reproducibility. Here, we developed a new ligand exchange strategy to prepare ligand exchanged QD inks for single-step PbS film deposition. Compared with LbL deposition, the EQE of PbS QD photodetector made by single-step deposition has improved from 31% to 53%. The EQE and responsivity can be further improved to 95% with IR transparent electrode
Conference Chair
Columbia Univ. (United States)
Conference Chair
Humboldt-Univ. zu Berlin (Germany)
Conference Chair
Iowa State Univ. of Science and Technology (United States)
Program Committee
Linköping Univ. (Sweden)
Program Committee
Univ. degli Studi di Cagliari (Italy)
Program Committee
The Univ. of Queensland (Australia)
Program Committee
Alon Gorodetsky
Univ. of California, Irvine (United States)
Program Committee
King Abdullah Univ. of Science and Technology (Saudi Arabia)
Program Committee
Univ. of Cambridge (United Kingdom)
Program Committee
Róisín M. Owens
Univ. of Cambridge (United Kingdom)
Program Committee
Univ. del Salento (Italy)
Program Committee
Univ. of St. Andrews (United Kingdom)
Program Committee
North Carolina State Univ. (United States)
Program Committee
Univ. of South Florida (United States)
Program Committee
Univ. degli Studi di Bari Aldo Moro (Italy)