Lee Kwanjae, Lee Hamin, Lee Cheul-Ro, Chung Tae-Hoon, Kim Yoon Seok, Leem Jae-Young, Jeong Kwang-Un, Kim Jin Soo
Opt Express. 2017 Jun 26;25(13):15152-15160. doi: 10.1364/OE.25.015152.
We report a possible way to extend the emission wavelength of InyGayN/InxGaxN quantum-well (QW) light-emitting diodes (LEDs) to the yellow-red spectral range with little degradation of the radiative efficiency. The InyGayN well with high indium (In) content (HI-InyGayN) was realized by periodic Ga-flow interruption (Ga-FI). The In contents of the HI-InyGayN well and the InxGaxN barrier were changed to manipulate the emission wavelength of the LEDs. An InGaN/InGaN-QW LED, grown by continuous growth mode (C-LED), was prepared as a reference. The photoluminescence (PL) wavelengths of the HI-InyGayN/InxGaxN QW LEDs were changed from 556 to 597 nm. The PL intensity of the HI-InyGayN/InxGaxN LED with a peak wavelength of 563 nm was 2.7 times stronger than that of the C-LED (λ = 565 nm). The luminescence intensity for the HI-InyGayN/InxGaxN QW LED emitting at 597 nm was stronger than those of the other LED samples with shorter wavelengths. Considering the previous works on degradation in crystal quality and increase in the quantum-confined Stark effect with increasing In content in InGaN, the approach in this work is very promising for yellow-red InGaN LEDs.
我们报道了一种可能的方法，可将InyGayN/InxGaxN量子阱（QW）发光二极管（LED）的发射波长扩展至黄红色光谱范围，同时辐射效率几乎不降低。通过周期性中断镓流（Ga-FI）实现了具有高铟（In）含量的InyGayN阱（HI-InyGayN）。改变HI-InyGayN阱和InxGaxN势垒中的铟含量，以控制LED的发射波长。制备了通过连续生长模式生长的InGaN/InGaN-QW LED（C-LED）作为参考。HI-InyGayN/InxGaxN QW LED的光致发光（PL）波长从556 nm变为597 nm。峰值波长为563 nm的HI-InyGayN/InxGaxN LED的PL强度比C-LED（λ = 565 nm）强2.7倍。发射波长为597 nm的HI-InyGayN/InxGaxN QW LED的发光强度比其他波长较短的LED样品更强。考虑到之前关于InGaN中铟含量增加导致晶体质量下降和量子限制斯塔克效应增强的研究工作，这项工作中的方法对于黄红色InGaN LED非常有前景。
