Solution preparation of molybdenum oxide on graphene: a hole transport layer for efficient perovskite solar cells with a 1.12 V high open-circuit voltage

摘要

Recently, based on the tremendous progresses in performance of perovskite solar cells (PSCs), the inverted planar PSCs have attracted attentions for future applications. Since the traditional poly(3,4-ethylenedioxythiophene) hole transport layer could cause a loss of open-circuit voltage (V_(oc)), some organic and inorganic alternatives have been widely investigated. However, the V_(oc) is still below for the demand of optimized value. Here, we demonstrate that the reduced graphene oxide (RGO) doping is a facile and effective method to make molybdenum oxide (MoO_x) as a promising hole transport layer (HTL) for high-performance PSCs. The conductive MoO_x:RGO HTL can facilitate perovskite crystallization and reduce the potential losses of V_(oc) in devices. Thus, a high PCE of up to 18.15% is achieved which simultaneously possesses a high V_(oc) of 1.12 V. With this strategy, the MoO_x:RGO provides a novel hole transport layer for high performance and decently stable optoelectronic devices. More importantly, it opens up the research significance of doping in inorganic buffer interlayers for the perovskite solar cells.