Recently, all-inorganic perovskite CsPbBr3 has been shown to be promising for light-emitting diode applications because of its higher thermal stability and photoluminescence quantum efficiency. However, the performance of all-inorganic perovskite applied to PeLED devices still needs to be further improved. In this paper, a strategy to modify the PEDOT:PSS transport layer with ammonia was successfully developed, and an all-inorganic perovskite light-emitting diode with a ITO/PEDOT:PSS/CsPbBr3/TPBi/LiF/Al structure was fabricated. It is shown that the ammonia-modified PEDOT:PSS not only improved the interfacial energy barrier between the PEDOT:PSS and CsPbBr3 layer which effectively improved the charge injection balance rate and then decreased the turn-on voltage of the proposed devices from 2.6 V to 2.3 V. In addition, the maximum luminance of the devices was increased by 5 times (2540 Cd/m2 to 14025Cd/m2), and both the current efficiency and external quantum efficiency (EQE) were enhanced 2.6 fold (1.61Cd/A to 4.17Cd/A and 0.45%–1.16% respectively). The mechanism was investigated and was found to be due to the enhancement of the peak ratio of the intensity (I(100)/I(110)) of the CsPbBr3 layer, which effectively improved the band edge radiative recombination. The PEDOT:PSS transport layer with ammonia not only lowered the interfacial energy barrier but also improved the morphology and changed the crystallization of the CsPbBr3 layer.
All Science Journal Classification (ASJC) codes
- 化學 (全部)