TY - JOUR
T1 - Role of cation-mediated recombination in perovskite solar cells
AU - Singh, Ajay
AU - Kaiser, Waldemar
AU - Gagliardi, Alessio
N1 - Publisher Copyright:
© 2020
PY - 2021/3
Y1 - 2021/3
N2 - The origin of the hysteresis in the current–voltage (J–V) characteristics in perovskite solar cells (PSCs) is one of the most debated topics of recent years. Hysteretic effects are connected with the slow redistribution of ionic defects during the voltage sweep. Existing literature focuses on the potential screening due to accumulated ions, solely, while neglecting the possibility of charge trapping and subsequent recombination via ions. We investigate the role of cation-mediated recombination of ions using time-dependent drift–diffusion simulations in MAPbI3 PSCs. Slow-moving cations are considered as traps for the electrons. Trapped electrons can subsequently recombine non-radiatively with holes. We analyze the role of the cation-mediated trapping and its parameters (capture coefficient, cation energy, ion mobility) as well as the scan rate on the device performance. For shallow cation energies, a decrease in open-circuit voltage and slight enhancement in hysteresis is observed. Deep cation energies lead to a substantial deterioration of device performance and large hysteresis enhancement. The presented study emphasizes the importance of considering the interaction of ions with charge carriers beyond the simple electrostatic models to improve our understanding of PSCs.
AB - The origin of the hysteresis in the current–voltage (J–V) characteristics in perovskite solar cells (PSCs) is one of the most debated topics of recent years. Hysteretic effects are connected with the slow redistribution of ionic defects during the voltage sweep. Existing literature focuses on the potential screening due to accumulated ions, solely, while neglecting the possibility of charge trapping and subsequent recombination via ions. We investigate the role of cation-mediated recombination of ions using time-dependent drift–diffusion simulations in MAPbI3 PSCs. Slow-moving cations are considered as traps for the electrons. Trapped electrons can subsequently recombine non-radiatively with holes. We analyze the role of the cation-mediated trapping and its parameters (capture coefficient, cation energy, ion mobility) as well as the scan rate on the device performance. For shallow cation energies, a decrease in open-circuit voltage and slight enhancement in hysteresis is observed. Deep cation energies lead to a substantial deterioration of device performance and large hysteresis enhancement. The presented study emphasizes the importance of considering the interaction of ions with charge carriers beyond the simple electrostatic models to improve our understanding of PSCs.
KW - Cation-mediated recombination
KW - Drift–diffusion model
KW - Ionic defects
KW - J–V hysteresis
KW - Perovskite solar cell
UR - http://www.scopus.com/inward/record.url?scp=85097336825&partnerID=8YFLogxK
U2 - 10.1016/j.solmat.2020.110912
DO - 10.1016/j.solmat.2020.110912
M3 - Article
AN - SCOPUS:85097336825
SN - 0927-0248
VL - 221
JO - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
M1 - 110912
ER -