Recent research progress on metal halide perovskite based visible light active photoanode for photoelectrochemical water splitting

Band gap engineering and photoluminescence tuning in halide double perovskites

“…A 2 M′ + M′′ 3+ X 6 halide double perovskite (HDP) and A 2 M 4+ X 6 vacancy-ordered HDP bulk powders, thin films, micro- and nanocrystals attract a great deal of interest owing to their broad compositional tunability and valuable optoelectronic properties. 1–7 One of the main advantages of HDPs that have made them attractive for optoelectronic applications is the ability to relatively simply tune their band gap to match the desired spectral range and achieve a high absorption efficiency in the UV-visible range. While it is not uncommon for pristine materials to demonstrate unsatisfactory intrinsic properties due to indirect band gaps or parity-forbidden electronic transitions, 8–10 a wide compositional tunability of HDPs comes in handy.…”