文章基本信息

标题：Mechanistic origin and unlocking of negative capacitance in perovskites solar cells
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作者：Mohd Taukeer Khan ; Peng Huang ; Abdullah Almohammedi 等
期刊名称：iScience
印刷版ISSN：2589-0042
出版年度：2021
卷号：24
期号：2
页码：1-17
DOI：10.1016/j.isci.2020.102024
语种：English
出版社：Elsevier
摘要：SummaryWe 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 thatp-i-ntype 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 witha p-i-nconfiguration is associated with the migration of halide ions and vacancies in the perovskite layers.Graphical AbstractDisplay OmittedHighlights•Negative capacitance inp-i-ndevice was unraveled from immittance spectroscopy•Under external bias, halide ions/vacancies migrate toward HTL/perovskites interface•Charge carriers discharge in trap states leading to the negative capacitance•Inp-i-ndevices PTAA-based HTL display improved charge transport compared with PEDOT:PSSEnergy Resources; Energy Systems; Energy Materials; Devices