Influence of surface passivation on perovskite CsPbBr1.2I1.8 quantum dots and application of high purity red light-emitting diodes

Lung-Chien Chen,Yen-Hung Tien,Jianjun Tian

doi:10.1016/j.jallcom.2021.162140

Abstract

In this work, trioctylphosphine oxide (TOPO) ligand is employed to improve the quality of CsPbBr1.2I1.8 quantum dots (QDs) films. Lead nitrate (Pb(NO3)2) is also used to passivate the surface of the films. The study of ligand and surface passivation on the luminous efficiency of red light-emitting diode (LED) is discussed. The CsPbBr1.2I1.8 QDs films co-doped with TOPO and Pb(NO3)2 can effectively improve the performance of the CsPbBr1.2I1.8 QDs LEDs due to reduction of non-radiation recombination of the carriers and smooth morphology in the active layer, thus improving the injection and transportation capabilities of carriers. As a result, the highest luminosity and current efficiency are 502.7 cd/m2 and 0.175 cd/A, respectively.

Highlights

Perovskite is a mineral composed of calcium, titanium and oxygen, and its chemical formula is CaTiO3 [1]
The CsPbBr1.2I1.8 quantum dots (QDs) films co-doped with trioctylphosphine oxide (TOPO) and Pb(NO3)2 can effectively improve the performance of the CsPbBr1.2I1.8 QDs light-emitting diode (LED) due to reduction of non-radiation recombination of the carriers and smooth morphology in the active layer, improving the injection and transportation capabilities of carriers
The size distribution of QD particles appeared barely change, but condensation and compact as the concentration of TOPO added into the solution of CsPbBr1.2I1.8 QDs increases due to self-aggregation effect [22,23]

Summary

Introduction

Perovskite is a mineral composed of calcium, titanium and oxygen, and its chemical formula is CaTiO3 [1]. Any compound represented by the general formula ABX3 can be called perovskite. Material of A site can be divided into all-inorganic perovskite and organic-inorganic mixed type perovskite. A can be composed of monovalent organic cations, such as CH3NH3+ (methylammonium, MA+) or CH(NH2)2+ (formamidinium, FA+), B is composed of divalent metal cations, usually lead ion Pb2+ or tin ion Sn2+, and X is a halogen anion, mainly Cl-, Br- or I- [2,3,4,5]. MAPbX3 and CsPbX3 active layer in device structure mainly used in solar cells, photodetectors, optoelectronic devices, and light-emitting diodes (LEDs) [6,7,8,9,10,11,12,13,14]

Methods

Results

Conclusion