Design of Distributed Bragg Reflectors for Green Light-Emitting Devices Based on Quantum Dots as Emission Layer

Abstract

Light-emitting diodes based on quantum dots as an active emission can be considered as a promising next generation for application in displays and lighting. We report a theoretical investigation of green emission at 550 nm of microcavity inorganic–organic light-emitting devices based on Zn (Te, Se) alloy quantum dots as an active layer. Distributed Bragg Reflector (DBR) has been applied as a bottom mirror. The realization of high-quality DBR consisting of both high and low refractive index structures is investigated. The structures applied for high refractive index layers are (ZrO2, SiNx, ZnS), while those applied for low index layers are (Zr, SiO2, CaF2). DBR of ZnS/CaF2 consisting of three pairs with a high refractive index step of (Δn = 0.95) revealed a broad stop bandwidth (178 nm) and achieved a high reflectivity of 0.914.

Keywords

• Zn (Te, Se) alloy quantum dot
• organic light-emitting devices
• green emission
• distributed Bragg reflector