Proposed materials modeling center for improving electro-optical devices
Electro-optical semiconductors are components used in IR imagers, UV detectors, and UV emitters. The process of developing new devices that include these semiconductors requires a good understanding of materials synthesis, device operation, and design-controllable parameters. All of these can be obtained from a robust process of multi-scale modeling and validation.1–6 To that end, and to realize the timely transition of new electro-optical technology from demonstration to system deployment, the US Army Research Laboratory (ARL) is currently pursuing a new research and development project.
The Center for Electro-Optical Semiconductor Materials Modeling (CEOSM2) has thus been proposed. The work of CEOSM2 is focused on modeling electro-optical semiconductor devices. The project would be a partnership between the US government, industry, and academia. Each partner would therefore be able to tap the Army's expertise, facilities, and capabilities to increase the efficiency of technology transition.7
In this work, we aim to model the operation of the research center on two existing examples. The first example—the Center for Research in Extreme Batteries (CREB)—has the goal of advancing battery technology for extreme environments. Second, the Specialty Electronics Center (SEC) is focused on providing access to state-of-the-art materials growth and processing facilities. Both centers rely on each partner's willingness to use their own research budgets to reach goals chosen by a steering committee (comprised of representatives from the partner organizations).
Our portfolio at ARL also includes the Enterprise for Multiscale Research of Materials (EMRM). It is through this project that we are developing the scientific foundation and design tools for modeling, design, analysis, prediction, and behavioral control of novel materials—from atomistic to continuum—in both temporal and spatial scales under extreme conditions. These expanding capabilities enable the exploration of physical interactions in the presence of defects, surfaces, and interfaces within the materials. Our approach includes theory, validated modeling at and across multiple scales, experimentation, characterization, identification of material metrics, as well as materials synthesis and processing. An example of our method is modeling the location of interface formation within a structure to obtain optimum quantum efficiency. The scope of the EMRM is broad, including semiconductors, metals, ceramics, and computational methods and hardware.
One recent success from our EMRM work is the use of inputs, from smaller scale to a large scale, to analyze the performance of an experimental extended shortwave IR photodetector. We used the input from the lower-scale results to remove some unknowns in the higher-scale calculation. In this way, we were able to simplify the higher-scale model.5, 6 The understanding at the lower level also contributed significantly to the understanding at the higher level. Conceivably, we could apply this knowledge in device development.
Building on the progress of the CREB and SEC, and the capabilities being built under the EMRM, the CEOSM2 will accelerate new, focused collaborative research on modeling and performance of semiconductor materials and devices. As envisioned, the work of the CEOSM2 will benefit all partners by improving current materials, facilitating the discovery of new semiconductor materials, and transforming these into useable devices through 3D multiscale modeling. In addition, CEOSM2 will allow all partners to have access to the Department of Defense's high-performance computing resources, and will permit the strengths of each partner to be capitalized. The model for the CEOSM2 is depicted graphically in Figure 1.
In summary, we have modeled the operation of the ARL's proposed Center for Electro-Optical Semiconductor Materials Modeling. We have based our model on recent work that we have conducted for the Center for Research in Extreme Batteries, the Speciality Electronics Center, and the Enterprise for Multiscale Resarch for Materials. To further the project's progress, we need to undertake critical discussions with potential partners. In 2016, an ARL team will actively pursue such dialogs and will campaign for the initiation of CEOSM2.
Philip Perconti currently serves as director of the Sensors and Electron Devices Directorate, and is the lead for ARL's Materials Research Campaign. He is responsible for the Army's primary basic and applied research program for sensors, electronics, signal processing, as well as power and energy component technologies.
W. C. Kirkpatrick Alberts II is a physicist in the Sensors and Electron Devices Directorate. His research interests include aspects of outdoor sound propagation (from infrasonic through audible frequencies), wind noise suppression, and associated signal processing.
Jagmohan Bajaj is an advisor to the director of the Sensors and Information Sciences Directorate. He assists in determining strategic research directions and in locating opportunities to advance the state-of-the-art in semiconductor materials and for potential areas for technology transition.
Jonathan Schuster is an Oak Ridge Associated Universities post-doctoral fellow in the Sensors and Electron Devices Directorate. His research is focused on modeling of semiconductor materials for Army applications.
Meredith Reed is the team leader of the Nitride Optoelectronics Team in the Sensors and Electron Devices Directorate and is the cooperative agreement manager for the Multiscale Multidisciplinary Modeling of Electronic Materials Collaborative Research Alliance. Her research is focused on wide-bandgap UV optoelectronic materials.