Search

Perovskite solar cells (PSCs) represent a promising next‐generation photovoltaic technology considering their high efficiency and low cost. At the current stage, resolving the stability bottleneck is extremely urgent to realize PSCs' commercialization since the efficiencies of these cells are improved to a level comparable to that of crystalline silicon solar cells. Similar to other functional layers, a proper choice of the rear electrode atop the perovskite layer is equally important for achieving the device's long‐term stability. This topic has not been comprehensively reviewed before. Here, recent progress in the development of rear electrodes based on metals, carbon‐based materials, transparent conductive oxides, and conductive polymers is summarized, especially focusing on their different impacts on the device's long‐term stability and associated degradation mechanisms. In the context of practical applications, the impacts of rear electrode materials on the device's overall efficiency and cost‐effectiveness are also discussed. [ABSTRACT FROM AUTHOR]

Optical loss is one of the main factors that restrict the power conversion efficiency (PCE) of perovskite solar cells (PSCs). Anti-reflective coating and light-trapping structure is one of the effective methods to enhance light capture and thus improve PCE. Through the finite-difference time-domain (FDTD) method, polydimethylsiloxane (PDMS) anti-reflection coatings with different light-trapping structures were introduced in the air–glass interface of planar heterojunction-based PSCs. Calculating the optical absorption, the inverted-pyramid structure had the best anti-reflection performance. On this basis, in order to further improve photon absorption of perovskite layers, an optical coupling structure with double-decker inverted pyramids are designed by inserting an inverted pyramid structure between perovskite layer and TiO 2. According to the cross-sectional | E | 2 distribution of the EM wave inside the device, three different marshalling patterns of the optical coupling structure are proposed and studied to select the best one for PSCs. This kind of marshalling pattern can highly enhance light harvesting of perovskite solar cells, thus increasing the generation rate of charge carrier in perovskite layers and improving the PCE. [ABSTRACT FROM AUTHOR]

The hole transport layer (HTL) free carbon based perovskite solar cells (Carbon PSC) are known for low cost, good stability and commercial manufacturing technology. Compared to the structure of traditional cells, the carrier transport performance between the absorber layer and the carbon electrode (CE) is poor. As an excellent P-type material, NiO has been doped in CE for obtaining a better performance of PSCs. However, NiO will inevitably reduce the conductivity of the CE due to the poor conductivity, thus failing to fully exploit the advantages of NiO in hole extraction. In this paper, rGO/NiO composites were successfully prepared by doping rGO with good conductivity, which not only improved the conductivity of the CE, but also ensured good hole extraction of the doped CE. The carrier transport in the cell was significantly improved, resulting in 32% increase in the short circuit current density (J sc). The performance of perovskite solar cells was optimized by doping the CE, and the power conversion efficiency (PCE) of the cell was increased from 5.48% to 8.50%. [ABSTRACT FROM AUTHOR]