Screened Charge Carrier Transport in Methylammonium Lead Iodide Perovskite Thin Films.
While organometal halide perovskites are promising for a variety of optoelectronic applications, the morphological and compositional defects introduced by solution processing techniques have hindered efforts at understanding their fundamental properties. To provide a detailed picture of the intrinsic carrier transport properties of methylammonium lead iodide without contributions from defects such as grain boundaries, we utilized pump-probe microscopy to measure diffusion in individual crystalline domains of a thin film. Direct imaging of carrier transport in 25 individual domains yields diffusivities between 0.74 and 1.77 cm2s-1, demonstrating single-crystal-like, long-range transport characteristics in a thin film architecture. We also examine the effects of excitation density on carrier diffusivity, finding that transport is nearly independent of photoexcited carrier density between 6 × 1017cm-3and 4 × 1019cm-3. Transport modeling of the observed density independence suggests that strong carrier-phonon scattering coupled with a large static relative permittivity is responsible for the unusual transport characteristics of methylammonium perovskite.
Montana Materials Science Program and ‡Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States.
Andrew H
AH
Hill
Montana Materials Science Program and ‡Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States.
Kori E
KE
Smyser
Montana Materials Science Program and ‡Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States.
Casey L
CL
Kennedy
Montana Materials Science Program and ‡Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States.
Eric S
ES
Massaro
Montana Materials Science Program and ‡Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States.
Erik M
http://orcid.org/0000-0002-0568-3889
EM
Grumstrup