To unravel the impact of defects in the local charge carrier dynamics of lead-halide perovskite thin films, we employ transient absorption microscopy, which couples ultrafast temporal resolution with ~200 nm spatial resolution, to locally interrogate charge carrier cooling, transport, and recombination in individual domains. Ultrafast imaging of charge carrier diffusion shows significant domain-to-domain variation in carrier mobility within a single thin film. Direct correlation of these spectroscopic measurements to scanning electron microscopies reveals a strong dependence on domain size and quality. We also examine the effects of surface states and carrier density on the effective mobility and discuss implications for photovoltaics and other optoelectronic devices.

Date Published: 8 May 2017
PDF: 8 pages
Proc. SPIE 10193, Ultrafast Bandgap Photonics II, 101930W (8 May 2017); doi: 10.1117/12.2262664

Published in SPIE Proceedings Vol. 10193:
Ultrafast Bandgap Photonics II
Michael K. Rafailov, Editor(s)