Ricerc@Sapienza

Perovskite (CH3NH3PbI3) solar cells (PSCs) were produced in the inverted architecture employing transparent nickel oxide (NiO) as hole transporting layer (HTL). The different functional layers of the photoconversion device were solution processed in ambient conditions the HTL of NiO being prepared via sol-gel and successively deposited by spin-coating. The conditions of preparation of the transparent HTL were optimized through the stabilization of the nickel-containing sol with bulky alcohols and strong inorganic acids.

Hole-collecting and buffer layers more transparent than amorphous silicon layers are regarded as one of the possible improvements needed in amorphous/crystalline silicon heterojunctions to help reach the limit efficiency of silicon-based solar cells. Recent studies have demonstrated the suitability of sub-stoichiometric molybdenum oxide (MoOx) as hole-extracting layer in heterojunction solar cells based on n-type crystalline silicon. However, up to now MoOx has mainly been used in combination with amorphous silicon, so limiting its potential as a transparent emitter.