TY - JOUR
T1 - Planar versus mesoscopic perovskite microstructures
T2 - The influence of CH3NH3PbI3 morphology on charge transport and recombination dynamics
AU - Pascoe, Alexander R.
AU - Yang, Mengjin
AU - Kopidakis, Nikos
AU - Zhu, Kai
AU - Reese, Matthew O.
AU - Rumbles, Garry
AU - Fekete, Monika
AU - Duffy, Noel W.
AU - Cheng, Yi Bing
PY - 2016/4/1
Y1 - 2016/4/1
N2 - Perovskite solar cells (PSCs) employing planar and mesoscopic architectures have both resulted in high efficiency devices. However, there is presently a limited understanding of the inherent advantages of both systems, particularly in terms of the charge transport and recombination dynamics. In the present study we characterize the relative benefits of the two most prominent CH3NH3PbI3 morphologies, primarily through time-resolved microwave conductivity (TRMC) and time-resolved photoluminescence (TRPL) measurements. The comparatively large perovskite grains, typical of planar assemblies, exhibited higher charge mobilities and slower trap-mediated recombination compared to the mesoscopic architectures. These findings reveal the injurious influence of grain boundaries on both charge transport and recombination kinetics, and suggest an innate advantage of planar morphologies. However, through impedance spectroscopy (IS) measurements, mesoscopic architectures were found to limit the interfacial recombination at the transparent conductive oxide (TCO) substrate. The lessons learnt through the characterization measurements were subsequently utilized to produce an optimized cell morphology, resulting in a maximum conversion efficiency of 16%.
AB - Perovskite solar cells (PSCs) employing planar and mesoscopic architectures have both resulted in high efficiency devices. However, there is presently a limited understanding of the inherent advantages of both systems, particularly in terms of the charge transport and recombination dynamics. In the present study we characterize the relative benefits of the two most prominent CH3NH3PbI3 morphologies, primarily through time-resolved microwave conductivity (TRMC) and time-resolved photoluminescence (TRPL) measurements. The comparatively large perovskite grains, typical of planar assemblies, exhibited higher charge mobilities and slower trap-mediated recombination compared to the mesoscopic architectures. These findings reveal the injurious influence of grain boundaries on both charge transport and recombination kinetics, and suggest an innate advantage of planar morphologies. However, through impedance spectroscopy (IS) measurements, mesoscopic architectures were found to limit the interfacial recombination at the transparent conductive oxide (TCO) substrate. The lessons learnt through the characterization measurements were subsequently utilized to produce an optimized cell morphology, resulting in a maximum conversion efficiency of 16%.
KW - Perovskite
KW - Solar cells
KW - Time-resolved microwave conductivity
KW - Time-resolved photoluminescence
UR - http://www.scopus.com/inward/record.url?scp=84959453900&partnerID=8YFLogxK
U2 - 10.1016/j.nanoen.2016.02.031
DO - 10.1016/j.nanoen.2016.02.031
M3 - Article
AN - SCOPUS:84959453900
VL - 22
SP - 439
EP - 452
JO - Nano Energy
JF - Nano Energy
SN - 2211-2855
ER -