An interface stabilized perovskite solar cell with high stabilized efficiency and low voltage loss

Abstract

Stabilization of the crystal phase of inorganic/organic lead halide perovskites is critical for their high performance optoelectronic devices. However, due to the highly ionic nature of perovskite crystals, even phase stabilized polycrystalline perovskites can undergo undesirable phase transitions when exposed to a destabilizing environment.While various surface passivating agents have been developed to improve the device performance of perovskite solar cells, conventional deposition methods using a protic polar solvent, mainly isopropyl alcohol (IPA), results in a destabilization of the underlying perovskite layer and an undesirable degradation of device properties. We demonstrate the hidden role of IPA in surface treatments and develop a strategy in which the passivating agent is deposited without destabilizing the high quality perovskite underlayer. This strategy maximizes and stabilizes device performance by suppressing the formation of the perovskite d-phase and amorphous phase during surface treatment, which is observed using conventional methods. Our strategy also effectively passivates surface and grain boundary defects, minimizing non-radiative recombination sites, and preventing carrier quenching at the perovskite interface. This results in an opencircuit-voltage loss of only B340 mV, a champion device with a power conversion efficiency of 23.4% from a reverse current-voltage scan, a device with a record certified stabilized PCE of 22.6%, and enhanced operational stability. In addition, our perovskite solar cell exhibits an electroluminescence external quantum efficiency up to 8.9%. Fig. 4 (a) 3D/LP PSC devices with efficiencies measured at MIT and at Newport. (b) Asymptotical measurement on stabilized open-circuit-voltage (V OC,S ). (c) Stabilization of current density. (d) Stabilized J-V curve extracted from (b and c) with stabilized power conversion efficiency (PCE S ) of 22.6%.

Tailored Amphiphilic Molecular Mitigators for Stable Perovskite Solar Cells with 23.5% Efficiency

“…Sherkar et al showed that trap‐assisted recombination at the interface between HTL and the perovskite is the dominant loss mechanism 10. Thus, surface passivation of the perovskite is considered the most effective approach to suppress nonradiative recombination losses and, concomitantly, improve the photovoltage 11. Tavakoli et al showed that by surface passivation of the perovskite with adamantine amine a PCE of 20.93% can be achieved for mesoscopic PSCs 12.…”

Spontaneously Self‐Assembly of a 2D/3D Heterostructure Enhances the Efficiency and Stability in Printed Perovskite Solar Cells

“…Much effort has thus been devoted to surface passivation by post‐depositing a solution of aliphatic or aromatic alkyl ammonium cations, thereby forming a thin layer of 2D perovskite like PEA 2 PbI 4 , [ 27 ] BA 2 PbI 4 , [ 28 ] AVAPbI 4 , [ 7,25 ] etc. [ 29,30 ] The superior stability of the 2D/3D structure PSCs was manifested by a recent encouraging work where a one‐year stable PSC with a 2D/3D heterostructure was reported. [ 7 ] Nevertheless, the commonly used two‐step procedure for preparation of 2D/3D heterostructures increases the complexity in device fabrication.…”

Controlling the Growth Kinetics and Optoelectronic Properties of 2D/3D Lead–Tin Perovskite Heterojunctions

“…Finally, the ability to tune the fraction of 2D and 3D components on the surface and the bulk opens up these heterostructures for a range of device applications. Recently, it was reported that the surface passivation of bulk lead‐based 3D perovskite films with 2D molecules such as PEA through the post‐treatment processing of PEAI solutions can lead to extremely efficient and stable solar cells . In that system, the large‐bandgap 2D surface layer is sufficiently thin that charge injection to the contacts can still occur, though the layer still passivates trap states at the surfaces and grain boundaries of the 3D material.…”