Themed issue on perovskite solar cells: research on metal halide perovskite solar cells towards deeper understanding, upscalable fabrication, long-term stability and Pb-free alternatives

Solar cells or photovoltaic (PV) cells are semiconductor devices that convert solar energy into electricity. This technology is already being used to supply clean and renewable energy to society. However, currently installed PV capacity is still relatively low in many countries. Globally, the total generated electricity from PVs constitutes only ∼1% of worldwide electricity demands.1,2 Because solar energy is (i) plentiful (e.g., the amount of energy supplied to the earth within one day is sufficient to meet total global energy needs for one year) and (ii) clean, it is often mentioned as a solution to issues related to global warming and the current deficiency of global electricity demands for future society. Currently, silicon-based solar cells represent the dominant PV technology, accounting for ∼93% of total production, in which the shares of mono- and multi-crystalline silicon technology are ∼32% and ∼61%, respectively. The market share of all thin-film technologies amounts to ∼4.5% of total production: CdTe (2.3%), copper indium gallium diselenide or CIGS (1.9%), and amorphous-Si (0.3%).