Mechanistic origin and unlocking of negative capacitance in perovskites solar cells
Mohd Taukeer Khan,
Peng Huang,
Abdullah Almohammedi,
Samrana Kazim,
Shahzada Ahmad
Affiliations
Mohd Taukeer Khan
BCMaterials, Basque Center for Materials, Applications and Nanostructures, UPV/EHU Science Park, 48940 Leioa, Spain; Department of Physics, Faculty of Science, Islamic University of Madinah, Prince Naifbin Abdulaziz, Al Jamiah, Madinah 42351, Kingdom of Saudi Arabia
Peng Huang
BCMaterials, Basque Center for Materials, Applications and Nanostructures, UPV/EHU Science Park, 48940 Leioa, Spain
Abdullah Almohammedi
Department of Physics, Faculty of Science, Islamic University of Madinah, Prince Naifbin Abdulaziz, Al Jamiah, Madinah 42351, Kingdom of Saudi Arabia
Samrana Kazim
BCMaterials, Basque Center for Materials, Applications and Nanostructures, UPV/EHU Science Park, 48940 Leioa, Spain; IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Spain
Shahzada Ahmad
BCMaterials, Basque Center for Materials, Applications and Nanostructures, UPV/EHU Science Park, 48940 Leioa, Spain; IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Spain; Corresponding author
Summary: We have unlocked the mechanistic behavior of negative capacitance in perovskite solar cells (PSCs) by analyzing impedance spectra at variable photovoltage and applied bias, temperature-dependent capacitance versus frequency (C-f) spectra, and current-voltage (J-V) characteristics. We noted that p-i-n type PSCs having PEDOT:PSS or PTAA as hole transport layer display negative capacitance feature at low and intermediate frequencies. The activation energies (Ea) for the observance of negative capacitance were found to be in a similar order of magnitude required for the ionic migration. Moreover, the kinetic relaxation time (τkin) estimated to be in the same order of magnitude required to activate the halide ion migration. Our investigation suggests that the primary reason for the appearance of negative capacitance in PSCs with a p-i-n configuration is associated with the migration of halide ions and vacancies in the perovskite layers.
