Phosphomolybdic acid as an efficient hole injection material in perovskite optoelectronic devices.

Efficient perovskite devices consist of a perovskite film sandwiched between charge selective layers, in order to avoid non-radiative recombination. A common metal oxide used as a p-type or hole transport layer is molybdenum oxide. MoO3 is of particular interest for its very large work function, which allows it to be used both as an interfacial charge transfer material and a dopant for organic semiconductors.

Solution processed organic light-emitting diodes using a triazatruxene crosslinkable hole transporting material.

A cross-linkable triazatruxene that leads to insoluble films upon thermal annealing at temperatures compatible with flexible substrates is presented. The films were used as the hole transporting and electron blocking layer in partially solution processed phosphorescent organic light-emitting diodes, reaching power conversion efficiencies of 24 lm W, an almost 50% improvement compared to the same OLEDs without the cross-linkable hole transporting layer.