TY  - JOUR
AU  - Alvarez, Agustin O.
AU  - Arcas, Ramón
AU  - Aranda, Clara A.
AU  - Bethencourt, Loengrid
AU  - Mas-Marzá, Elena
AU  - Saliba, Michael
AU  - Fabregat-Santiago, Francisco
TI  - Negative Capacitance and Inverted Hysteresis: Matching Features in Perovskite Solar Cells
JO  - The journal of physical chemistry letters
VL  - 11
IS  - 19
SN  - 1948-7185
CY  - Washington, DC
PB  - ACS
M1  - FZJ-2021-00061
SP  - 8417 - 8423
PY  - 2020
AB  - Negative capacitance in the low-frequency domain and inverted hysteresis are familiar features in perovskite solar cells, which origin is still under discussion. Here we use impedance spectroscopy to analyze these responses in methylammonium lead bromide cells treated with lithium cations at the electron-selective layer/perovskite interface and in iodide devices exposed to different relative humidity conditions. Employing the surface polarization model, we obtain a time constant associated with the kinetics of the interaction of ions/vacancies with the surface, τkin, in the range of 100–102 s for all the cases exhibiting both features. These interactions lead to a decrease in the overall recombination resistance, modifying the low-frequency perovskite response and yielding a flattening of the cyclic voltammetry. As a consequence of these results we find that negative capacitance and inverted hysteresis lead to a decrease in the fill factor and photovoltage values.
LB  - PUB:(DE-HGF)16
C6  - 32903005
UR  - <Go to ISI:>//WOS:000577152900071
DO  - DOI:10.1021/acs.jpclett.0c02331
UR  - https://juser.fz-juelich.de/record/889136
ER  -