Title Information
Title
Direct Optical Characterization of Carrier Transport and Structural Properties in Halide Perovskite Materials
Name: Personal
Name Part
Li, Wenhao
Role
Role Term: Text
creator
Name: Personal
Name Part
Zia, Rashid
Role
Role Term: Text
Advisor
Name: Personal
Name Part
Padture, Nitin P.
Role
Role Term: Text
Reader
Name: Personal
Name Part
Pelcovits, Robert
Role
Role Term: Text
Reader
Name: Corporate
Name Part
Brown University. Department of Physics
Role
Role Term: Text
sponsor
Origin Information
Copyright Date
2019
Physical Description
Extent
, None p.
digitalOrigin
born digital
Note: thesis
Thesis (Ph. D.)--Brown University, 2019
Genre (aat)
theses
Abstract
Perovskite solar cells have attracted considerable attention in recent years due to their rapidly increasing power conversion efficiency, which currently exceeds 24%. Despite this success achieved through improvements in the fabrication processes and compositional engineering, the underlying optoelectronic properties of these materials, including charge transport, remain controversial. Here we studied carrier transport in perovskite materials using two related photoluminescence spectroscopy methods. First, we developed a time-resolved photoluminescence imaging method for studying carrier diffusion in formamidinium lead triiodide (FAPbI3) perovskite thin films. With this method, it was found that carrier diffusivity increases when background carriers are present. This effect may be explained by trap-carrier interactions. Second, a steady state photoluminescence method was developed to study carrier diffusion. In particular it was used to study carrier transport barriers and help identify sub-grain special boundaries in FAPbI3 perovskite thin films. Interestingly, these boundaries which restrict carrier diffusion and serve as nonradiative recombination sites, cannot be observed by conventional AFM or SEM measurements. The presence of such boundaries may explain why the performance of perovskite solar cells has not scaled with apparent grain size. With this same method, carrier transport across ferroelastic twin boundaries (FTB) was studied in methylammonium lead triiodide (MAPbI3) single crystals. It was found that FTBs have little effect on carrier transport and recombination, this in contrast both to normal grain boundaries and special subgrain boundaries.
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01062037")
Topic
Photoluminescence--Measurement
Language
Language Term (ISO639-2B)
English
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20200720
Access Condition: rights statement (href="http://rightsstatements.org/vocab/InC/1.0/")
In Copyright
Access Condition: restriction on access
Collection is open for research.
Type of Resource (primo)
dissertations