Organometal halide perovskite as hole injection enhancer in organic light-emitting diode

We introduce an organometal halide perovskite (CH₃NH₃PbI₃), as a hole injection layer (HIL) to accelerate hole injection and transport in tris-(8-hydroxyquinoline) aluminum-based organic light-emitting diodes (OLEDs). The excellent charge mobility of CH₃NH₃PbI₃ along with the better interface contacts induced by the CH₃NH₃PbI₃ HIL improved the charge balance and thus enhanced device performance compared with that of OLEDs without a HIL and with a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) HIL. Maximum luminance of 19110 cd m⁻² and power efficiency of 3.210 lm W⁻¹ were obtained. Also, besides more balanced charge recombination, the non-aqueous fabrication of the perovskite HIL and the chemical stability of indium tin oxide in contact with CH₃NH₃PbI₃ led to increased device stability and durability, giving a half-life time as long as 31.7 h.