Limits to electrical mobility in lead-halide perovskite semiconductors

Journal article

Semiconducting polycrystalline thin films are cheap to produce and can be deposited on flexible substrates, yet high-performance electronic devices usually utilize single-crystal semiconductors, owing to their superior charge-carrier mobilities and longer diffusion lengths. Here we show that the electrical performance of polycrystalline films of metal-halide perovskites (MHPs) approaches that of single crystals at room temperature. Combining temperature-dependent terahertz conductivity measurements and ab initio calculations we uncover a complete picture of the origins of charge-carrier scattering in single crystals and polycrystalline films of CH3NH3PbI3. We show that Fröhlich scattering of charge carriers with multiple phonon modes is the dominant mechanism limiting mobility, with grain-boundary scattering further reducing mobility in polycrystalline films. We reconcile the large discrepancy in charge-carrier diffusion lengths between single crystals and films by considering photon reabsorption. Thus, polycrystalline films of MHPs offer great promise for devices beyond solar cells, including light-emitting diodes and modulators.

Authors: Xia, CQ; Peng, J; Poncé, S; Patel, JB; Wright, AD

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Chemical Society
• Journal: Journal of Physical Chemistry Letters
• Volume: 12
• Issue: 14
• Pages: 3607–3617
• Publication date: 2021-04-06
• Acceptance date: 2021-03-29
• DOI: 10.1021/acs.jpclett.1c00619
• EISSN: 1948-7185
• Language: English
• Keywords: FFR