ABSTRACT
Inorganic p-type materials are often considered as potential candidates in hole-transporting layer (HTL) in perovskite solar cells (PSC) because they possess higher hole mobility compared to their organic counterparts, as well as high chemical stability, flexibility, and inexpensive deposition methods. The employment of inorganic p-type materials for HTL in PSC follows two possibilities for device architecture: the “normal” structure and the “inverted” structure. Spiro-OMeTAD is a small molecule and exhibits low hole transporting which can be replaced by several inorganic materials such as copper thiocyanite and copper iodide. In an inverted architecture, a p-type inorganic mesoporous layer is deposited on the FTO layer, onto which the perovskite is formed. The normal structure has the fluorine-doped tin oxide (FTO) substrate as photoanode, which will collect electrons, and in the inverted architecture, the FTO substrate acts as photocathode-collecting holes. The crystal structure of perovskite was studied after a hole-transporting material was deposited on it.
