Although inorganic hole-transport materials usually possess high chemical stability, hole mobility, and low cost, the efficiency of most of inorganic hole conductor-based perovskite solar cells is still much lower than that of the traditional organic hole conductor-based cells. Here, we have successfully fabricated high quality CH3NH3PbI3 films on top of a CuSCN layer by utilizing a one-step fast deposition-crystallization method, which have lower surface roughness and smaller interface contact resistance between the perovskite layer and the selective contacts in comparison with the films prepared by a conventional two-step sequential deposition process. The average efficiency of the CuSCN-based inverted planar CH3NH3PbI3 solar cells has been improved to 15.6% with a highest PCE of 16.6%, which is comparable to that of the traditional organic hole conductor-based cells, and may promote wider application of the inexpensive inorganic materials in perovskite solar cells.

Hybrid organic–inorganic halide‐perovskite‐based solar cells have achieved notable progress. A hot topic in this field is exploring inexpensive, stable and effective hole‐transporting materials (HTMs) in order to improve the device performance and be favorable for large‐scale production in the future. The HTMs have been proven to be an important component of perovskite solar cells, which can form selective contact being favorable for reducing charge recombination and effective hole collection, thus resulting in the enhancement of the open‐circuit voltage and the fill factor. Here, an overview of the design and development of HTMs is given, mainly divided into conductive polymers, inorganic p‐type semiconductors in inverted‐structure‐based planar perovskite solar cells. The influences of their mobility, work function and film property on device performance are discussed.

Kesterite Cu2ZnSn(S,Se)4 solar cells fabricated from DMSO molecular solutions exhibit very different open circuit voltage (Voc) when tin precursor has different oxidation state (Sn2+ vs Sn4 ). Here, the grain...