Purpose

The purpose of this paper is to enhance the efficiency of the LED by introducing three-step magnesium (Mg) doping profile. Attention was paid to the effects of the Mg doping concentration of the first p-GaN layer (i.e. layer close to the active region). Attention was paid to the effects of the Mg doping concentration of the first p-GaN layer (i.e. layer close to the active region).

Design/methodology/approach

Indium gallium nitride (InGaN)–based light-emitting diode (LED) was grown on a 4-inch c-plane patterned sapphire substrate using metal organic chemical vapor deposition. The Cp₂Mg flow rates for the second and third p-GaN layers were set at 50 sccm and 325 sccm, respectively. For the first p-GaN layer, the Cp₂Mg flow rate varied from 150 sccm to 300 sccm to achieve different Mg dopant concentrations.

Findings

The full width at half maximum (FWHM) for the GaN (102) plane increases with increasing Cp₂Mg flow rate. FWHM for the sample with 150, 250 and 300 sccm Cp₂Mg flow rates was 233 arcsec, 236 arcsec and 245 arcsec, respectively. This result indicates that the edge and mixed dislocations in the p-GaN layer were increased with increasing Cp₂Mg flow rate. Atomic force microscopy (AFM) results reveal that the sample grown with 300 sccm exhibits the highest surface roughness, followed by 150 sccm and 250 sccm. The surface roughness of these samples is 2.40 nm, 2.12 nm and 2.08 nm, respectively. Simultaneously, the photoluminescence (PL) spectrum of the 250 sccm sample shows the highest band edge intensity over the yellow band ratio compared to that of other samples. The light output power measurements found that the sample with 250 sccm exhibits high output power because of sufficient hole injection toward the active region.

Originality/value

Through this study, the three steps of the Mg profile on the p-GaN layer were proposed to show high-efficiency InGaN-based LED. The optimal Mg concentration was studied on the first p-GaN layer (i.e. layer close to active region) to improve the LED performance by varying the Cp₂Mg flow rate. This finding was in line with the result of PL and AFM results when the samples with 250 sccm have the highest Mg acceptor and good surface quality of the p-GaN layer. It can be deduced that the first p-GaN layer doping has a significant effect on the crystalline quality, surface roughness and light emission properties of the LED epi structure.

中文翻译：

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p-GaN层三步掺杂镁对InGaN基发光二极管性能的影响

目的

本文的目的是通过引入三步镁 (Mg) 掺杂分布来提高 LED 的效率。关注第一p-GaN层（即靠近有源区的层）的Mg掺杂浓度的影响。关注第一p-GaN层（即靠近有源区的层）的Mg掺杂浓度的影响。

设计/方法/方法

使用金属有机化学气相沉积在 4 英寸 c 面图案化蓝宝石衬底上生长基于氮化铟镓 (InGaN) 的发光二极管 (LED)。第二和第三p-GaN层的Cp ₂ Mg流速分别设置为50 sccm和325 sccm。对于第一 p-GaN 层，Cp ₂ Mg 流速从 150 sccm 到 300 sccm 不等，以实现不同的 Mg 掺杂浓度。

发现

GaN (102) 面的半峰全宽 (FWHM) 随着 Cp ₂ Mg 流速的增加而增加。具有 150、250 和 300 sccm Cp ₂ Mg 流速的样品的 FWHM 分别为233 弧秒、236 弧秒和 245 弧秒。该结果表明 p-GaN 层中的边缘位错和混合位错随着 Cp _{2 的}增加而增加镁流速。原子力显微镜 (AFM) 结果表明，以 300 sccm 生长的样品表现出最高的表面粗糙度，其次是 150 sccm 和 250 sccm。这些样品的表面粗糙度分别为 2.40 nm、2.12 nm 和 2.08 nm。同时，与其他样品相比，250 sccm 样品的光致发光 (PL) 光谱在黄色带比上显示出最高的带边缘强度。光输出功率测量发现，由于向有源区注入了足够的空穴，250 sccm 的样品表现出高输出功率。

原创性/价值

通过这项研究，提出了 p-GaN 层上 Mg 轮廓的三个步骤，以展示高效的 InGaN 基 LED。在第一 p-GaN 层（即靠近有源区的层）上研究了最佳 Mg 浓度，以通过改变 Cp ₂ Mg 流速来改善 LED 性能。当 250 sccm 的样品具有最高的 Mg 受体和良好的 p-GaN 层表面质量时，这一发现与 PL 和 AFM 结果一致。可以推断出，第一p-GaN层掺杂对LED外延结构的晶体质量、表面粗糙度和发光性能有显着影响。