Prof Michael Johnston: Publications

Time-resolved THz spectroscopy of metal-halide perovskite single crystals and polycrystalline thin films

Institute of Electrical and Electronics Engineers (IEEE) 00 (2019) 1-2

Authors:

Chelsea Q Xia, Qianqian Lin, Jay B Patel, Adam D Wright, Timothy W Crothers, Rebecca L Milot, Laura M Herz, Michael B Johnston

Unveiling Temperature-Dependent Scattering Mechanisms in Semiconductor Nanowires Using Optical-Pump Terahertz-Probe Spectroscopy

Institute of Electrical and Electronics Engineers (IEEE) 00 (2019) 1-1

Authors:

Jessica L Boland, Francesca Amaduzzi, Sabrina Sterzl, Heidi Potts, Gözde Tütüncüoglu, Laura M Herz, Anna Fontcuberta I Morral, Michael B Johnston

Engineering III–V Nanowires for Optoelectronics: From Visible to Terahertz

Optica Publishing Group (2019) noth3b.1

Authors:

Hannah J Joyce, Chawit Uswachoke, Stephanie Adeyemo, Srabani Kar, Djamshid A Damry, Kun Peng, Michael B Johnston, Jennifer Wong-Leung, H Hoe Tan, Chennupati Jagadish

Elucidating the long-range charge carrier mobility in metal halide perovskite thin films

(2018)

Authors:

Jongchul Lim, Maximilian T Hoerantner, Nobuya Sakai, James M Ball, Suhas Mahesh, Nakita K Noel, Yen-Hung Lin, Jay B Patel, David P McMeekin, Michael B Johnston, Bernard Wenger, Henry J Snaith

Elucidating the long-range charge carrier mobility in metal halide perovskite thin films

Energy and Environmental Science Royal Society of Chemistry 12:1 (2018) 169-176

Authors:

Jongchul Lim, M Hoerantner, Nobuya Sakai, James M Ball, Suhas Mahesh, Nakita K Noel, Yen-Hung Lin, Jay B Patel, David P McMeekin, Michael B Johnston, Bernard Wenger, Henry J Snaith

Abstract:

Many optoelectronic properties have been reported for lead halide perovskite polycrystalline films. However, ambiguities in the evaluation of these properties remain, especially for long-range lateral charge transport, where ionic conduction can complicate interpretation of data. Here we demonstrate a new technique to measure the long-range charge carrier mobility in such materials. We combine quasi-steady-state photo-conductivity measurements (electrical probe) with photo-induced transmission and reflection measurements (optical probe) to simultaneously evaluate the conductivity and charge carrier density. With this knowledge we determine the lateral mobility to be ∼2 cm2 V−1 s−1 for CH3NH3PbI3 (MAPbI3) polycrystalline perovskite films prepared from the acetonitrile/methylamine solvent system. Furthermore, we present significant differences in long-range charge carrier mobilities, from 2.2 to 0.2 cm2 V−1 s−1, between films of contemporary perovskite compositions prepared via different fabrication processes, including solution and vapour phase deposition techniques. Arguably, our work provides the first accurate evaluation of the long-range lateral charge carrier mobility in lead halide perovskite films, with charge carrier density in the range typically achieved under photovoltaic operation.

91̽��