A perovskite based plug and play AC photovoltaic device with ionic liquid induced transient opto-electronic conversion

Abstract

This study reports on the implementation of transient opto-electronic conversion for energy harvesting associated with induced electric double layers (EDLs) at perovskite/ionic liquid interfaces. High speed alternating current (AC) producing photovoltaic devices are successfully fabricated and demonstrated with a device architecture as indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)/perovskite (CH₃NH₃PbI₃)/[6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM)/ionic liquid/aluminum (Al). 52% peak external quantum efficiency with a maximum responsivity of 228 mA W⁻¹ has been observed with a relatively uniform response over the whole visible solar spectrum. Such a new class of devices can produce photocurrent under both light “ON” and “OFF” cycles in response to a pulsed signal. This unique feature makes them inherently capable of producing AC power when illuminated under modulated solar radiation. The large (∼90 dB) linear dynamic range (LDR) of the devices confirms their efficient power conversion capabilities even from very low intensity light sources. At 50 Hz modulation frequency, a photovoltaic device with ∼2% overall effective AC power conversion efficiency, which further increases and gets saturated around ∼3% beyond 160 Hz modulation frequency, is also successfully realized. The mechanism of the AC effect formation is explained based on the energy band diagram and an equivalent resistance (R)–capacitance (C) circuit of the devices.