Charge carrier recombination dynamics in a bi-cationic perovskite solar cell

Abstract

A novel biphasic trap-assisted charge carrier recombination mechanism is proposed for a bi-cationic MAxFA1−xPbI3 perovskite solar cell.

Extraction technique of trap states based on transient photo-voltage measurement

“…Based on the hypothesis of exponential type DOS T distribution [46][47][48][49] , multiple-trapping model 46,[50][51][52] , and the zero-temperature approximation 46,52 , they find that when the DOS T distribution is exponential type, the logarithm of carrier lifetime and the photo-voltage satisfy linear relation. They use this relation to extract the DOS T distribution based on the TPV result [46][47][48] . Because of the hypothesis of exponential type distribution [46][47][48][49] , their method is effective only when the TPV result is linear.…”

“…They use this relation to extract the DOS T distribution based on the TPV result [46][47][48] . Because of the hypothesis of exponential type distribution [46][47][48][49] , their method is effective only when the TPV result is linear. The DOS T distribution extracted by their method is an exponential type distribution 46-48 . However, according to the TPV experiments reported in recent years [46][47][48] , the majority of TPV results are nonlinear.…”

“…In this article, we put forward a new technique for extraction of DOS T distribution based on the TPV measurement result. We give up the hypothesis of exponential type DOS T distribution [46][47][48][49] and zero-temperature approximation 46,52 . The method given in our work is based on the single hypothesis of multiple-trapping model 46,[50][51][52] .…”

“…We explain the slight deviation of E B and N T extracted by the two methods as follows. The analytic method is established based on the three hypothesis of multiple-trapping model 46,[50][51][52] , zero-temperature approximation 46,52 , and exponential type DOS T distribution [46][47][48][49] . Our numerical method is established based on the unique hypothesis of multiple-trapping model 46,[50][51][52] .…”

Modification of NiOx hole transport layer for acceleration of charge extraction in inverted perovskite solar cells

“…For the perovskite/quartz sample, the transient PL decay behavior exhibits a long carrier lifetime. The fast lifetime s 1 attributed to the band-to-band recombination is 40.63 ns, while the slow lifetime s 2 is 943.13 ns, which is closely related to the trap-assisted recombination 37,38. For the perovskite/HTL samples, s 1 is attributed to charge extraction process from perovskite to HTL.…”