An efficient CsPbBr3 perovskite light-emitting diode by employing 1,3,5-tri(m-pyrid-3-yl-phenyl)benzene as a hole and exciton blocking layer

An efficient perovkite light-emitting diode (PeLED) is fabricated by incorporating 1,3,5-tri (m-pyrid-3-yl-phenyl)benzene (TmPyPB) between the emitting layer (EML) and the electron transporting layer (ETL), where TmPyPB plays an indispensable blocking effect on both excitons and holes. It shows a maximum current efficiency of 9.37 cd/A, and the corresponding external quantum efficiency (EQE) of 2.42% with a saturated green color Commission International de I'Eclairage (CIE1993) coordinated of (0.1279, 0.7951) under a driving voltage of 6 V. Meanwhile, the operational lifetime of the TmPyPB-based PeLED is improved to about 2.6-fold to that of the one with only the traditional ETL of aluminum 8-hydroxyquinolinate (Alq3). The enhancements of electroluminescence (EL) performance are mainly attributed to better confinement of both the holes and the excitons in the EML, and more balanced carrier transportation in the TmPyPB-based PeLED. This work offers a feasible strategy to develop high performance optoelectronic devices. [Display omitted] •The EL performance and the stability of PeLEDs with a HEBL of TmPyPB were enhanced greatly.•The PeLEDs with a high purity green emission of color coordinated at (0.1279, 0.7951) were realized.•The electron transport ability was improved.•The excitons and holes were confined better.