Slow Dynamic Processes in Lead Halide Perovskite Solar Cells. Characteristic Times and Hysteresis.
Characteristic times of perovskite solar cells (PSCs) have been measured by different techniques: transient photovoltage decay, transient photoluminescence, and impedance spectroscopy. A slow dynamic process is detected that shows characteristic times in the seconds to milliseconds scale, with good quantitative agreement between transient photovoltage decay and impedance spectroscopy. Here, we show that this characteristic time is related with a novel slow dynamic process caused by the peculiar structural properties of lead halide perovskites and depending on perovskite crystal size and organic cation nature. This new process may lie at the basis of the current-voltage hysteresis reported for PSCs and could have important implications in PSC performance because it may give rise to distinct dynamical behavior with respect to other classes of photovoltaic devices. Furthermore, we show that low-frequency characteristic time, commonly associated with electronic carrier lifetime in other photovoltaic devices, cannot be attributed to a recombination process in the case of PSCs.
†Photovoltaics and Optoelectronic Devices Group, Departament de Fı́sica, Universitat Jaume I, 12071 Castelló, Spain.
Rafael S
RS
Sanchez
†Photovoltaics and Optoelectronic Devices Group, Departament de Fı́sica, Universitat Jaume I, 12071 Castelló, Spain.
Victoria
V
Gonzalez-Pedro
‡School of Chemical Engineering and Department of Energy Science, Sungkyunkwan University, Suwon 440-746, South Korea.
Jin-Wook
JW
Lee
‡School of Chemical Engineering and Department of Energy Science, Sungkyunkwan University, Suwon 440-746, South Korea.
Nam-Gyu
NG
Park
§Center for Next Generation Dye-Sensitized Solar Cells, Department of Energy Engineering, Hanyang University, Seoul 133-791, South Korea.
Yong Soo
YS
Kang
†Photovoltaics and Optoelectronic Devices Group, Departament de Fı́sica, Universitat Jaume I, 12071 Castelló, Spain.
Ivan
I
Mora-Sero
†Photovoltaics and Optoelectronic Devices Group, Departament de Fı́sica, Universitat Jaume I, 12071 Castelló, Spain.|∥Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia.
Juan
J
Bisquert
impedance spectroscopy; lead halide perovskite; perovskite solar cell; transient photovoltage decay