Pyrite‐Based Bi‐Functional Layer for Long‐Term Stability and High‐Performance of Organo‐Lead Halide Perovskite Solar Cells

Abstract

Organo‐lead halide perovskite solar cells (PSCs) have received great attention because of their optimized optical and electrical properties for solar cell applications. Recently, a dramatic increase in the photovoltaic performance of PSCs with organic hole transport materials (HTMs) has been reported. However, as of now, future commercialization can be hampered because the stability of PSCs with organic HTM has not been guaranteed for long periods under conventional working conditions, including moist conditions. Furthermore, conventional organic HTMs are normally expensive because material synthesis and purification are complicated. It is herein reported, for the first time, octadecylamine‐capped pyrite nanoparticles (ODA‐FeS2 NPs) as a bi‐functional layer (charge extraction layer and moisture‐proof layer) for organo‐lead halide PSCs. FeS2 is a promising candidate for the HTM of PSCs because of its high conductivity and suitable energy levels for hole extraction. A bi‐functional layer based on ODA‐FeS2 NPs shows excellent hole transport ability and moisture‐proof performance. Through this approach, the best‐performing device with ODA‐FeS2 NPs‐based bi‐functional layer shows a power conversion efficiency of 12.6% and maintains stable photovoltaic performance in 50% relative humidity for 1000 h. As a result, this study has the potential to break through the barriers for the commercialization of PSCs.

Room‐Temperature Vapor Deposition of Cobalt Nitride Nanofilms for Mesoscopic and Perovskite Solar Cells

“…In DSCs, Pt in counter electrodes is responsible for a large portion of manufacturing costs. Transition metal compounds with nanoarchitectures (i.e., large surface area) have shown Pt-like performance in DSCs, [34][35][36][37][38][39][40][41][42][43][44][45] and Cu compounds such as CuI [46] and CuSCN [47][48][49] and a number of oxides [50][51][52][53] and sulfides [54,55] manifested decent performance in PSCs. [30,31] Meanwhile, state-of-the-art organic hole transport materials used in PSCs are either costly or unfavorable for long-term operations.…”

Low‐Cost TiS2 as Hole‐Transport Material for Perovskite Solar Cells

“…Up to now, few inorganic p‐type semiconductors have been explored as HTMs, mainly due to the difficulty in one material meeting all the criteria for high performance, such as adequate hole mobility, high electrical conductivity, suitable energy level matching, and general structure stability. Accordingly, considering these limited choices for HTMs, only a few inorganic hole‐transporting materials such as CuSCN, CuI, NiO, Cu x O, and FeS 2 have been demonstrated in reaching low‐cost and stable devices. However, the choice of deposition method is also limited due to the sensitivity of the perovskite layer to a variety of solvents.…”

Incorporation of High-Mobility and Room-Temperature-Deposited CuxS as a Hole Transport Layer for Efficient and Stable Organo-Lead Halide Perovskite Solar Cells

“…According to the energy band study, Cu x S was not as effective as spiro in blocking electrons because of its lower conductive band level. Additionally, copper ions can react with perovskite through a replacement reaction, as illustrated in the literature . Finally, Cu x S is too conductive to act as an effective HTL.…”