The teachings herein relate to hole transport compounds containing cyclobutyl moieties that can be made into organic hole conductors and hole transport materials. Furthermore, optoelectronic and photoelectrochemical devices, in particular photovoltaic devices, organic-inorganic perovskite films, layered photovoltaic devices, p-n heterojunctions, dye-sensitized solar cells, organic solar cells and solid state solar cells, comprising such hole transport materials or hole transport compounds are described. It is notable that a perovskite solar cell module manufactured using the disclosed HTM compound exhibits a recording efficiency of more than 19.0% and an effective area of 30.24 cm2.