Improved hole injection for CsPbI3 nanocrystals based light-emitting diodes via coevaporation of hole transport layer

Abstract

To achieve balanced carrier transport and further improve the device performances of CsPbI3 nanocrystals-based light-emitting diodes, the 1,1-bis-(4-bis(4-tolyl)-aminophenyl) cyclohexene (TCTA) with high hole mobility was doped into a 4,4,4″-tris(carbazol-9-yl) triphenylamine hole transport layer (HTL) by a coevaporation method. The introduction of TAPC reduced hole injection barrier and improved mobility of the HTL. By adjusting the doping ratio of TAPC, highly efficient charge injection and more balanced carrier transport were obtained. Consequently, the mixed HTL based device showed elevated device performances with a maximum luminance of 3308 cd m−2 and a peak external quantum efficiency of 10.7%.