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Proceedings Paper

Charge-carrier dynamics in hybrid metal halide perovskites (Conference Presentation)
Author(s): Rebecca L. Milot; Waqaas Rehman; Giles E. Eperon; Henry J. Snaith; Michael B. Johnston; Laura M. Herz

Paper Abstract

Hybrid metal halide perovskites are attractive components for many optoelectronic applications due to a combination of their superior charge transport properties and relative ease of fabrication. A complete understanding of the nature of charge transport in these materials is therefore essential for current and future device development. We have evaluated two systems – the standard perovskite methylammonium lead triiodide (CH3NH3PbI3) and a series of mixed-iodide/bromide formamidinium lead perovskites – in an effort to determine what effect structural and chemical composition have on optoelectronic properties including mobility, charge-carrier recombination dynamics, and charge-carrier diffusion length. The photoconductivity in thin films of CH3NH3PbI3was investigated from 8 K to 370 K across three structural phases [1]. While the monomolecular charge-carrier recombination rate was found to increase with rising temperature indicating a mechanism dominated by ionized impurity mediated recombination, the bimolecular rate constant decreased with rising temperature as charge-carrier mobility declined. The Auger rate constant was highly phase specific, suggesting a strong dependence on electronic band structure. For the mixed-halide formamidinuim lead bromide-iodide perovskites, HC(NH2)2Pb(BryI1–y)3, bimolecular and Auger charge-carrier recombination rate constants strongly correlated with bromide content, which indicated a link with electronic structure [2]. Although HC(NH2)2PbBr3 and HC(NH2)2PbI3 exhibited high charge-carrier mobilities and diffusion lengths exceeding 1 μm, mobilities for mixed Br/I perovskites were all lower as a result of crystalline phase disorder.

Paper Details

Date Published: 11 November 2016
PDF: 1 pages
Proc. SPIE 9923, Physical Chemistry of Interfaces and Nanomaterials XV, 99230D (11 November 2016); doi: 10.1117/12.2238164
Show Author Affiliations
Rebecca L. Milot, Univ. of Oxford (United Kingdom)
Waqaas Rehman, Univ. of Oxford (United Kingdom)
Giles E. Eperon, Univ. of Oxford (United Kingdom)
Henry J. Snaith, Univ. of Oxford (United Kingdom)
Michael B. Johnston, Univ. of Oxford (United Kingdom)
Laura M. Herz, Univ. of Oxford (United Kingdom)

Published in SPIE Proceedings Vol. 9923:
Physical Chemistry of Interfaces and Nanomaterials XV
Artem A. Bakulin; Robert Lovrincic; Natalie Banerji, Editor(s)

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