Park Young Jae, Kim Hee Yun, Ryu Jae Hyoung, Kim Hyun Kyu, Kang Ji Hye, Han Nam, Han Min, Jeong Hyun, Jeong Mun Seok, Hong Chang-Hee
School of Semiconductor and Chemical Engineering, Chonbuk National University, Jeonju 561-756, South Korea.
Opt Express. 2011 Jan 31;19(3):2029-36. doi: 10.1364/OE.19.002029.
We report on the effect of embedded silica nanospheres on improving the performance of InGaN/GaN light-emitting diodes (LEDs). The silica nanospehres were coated on the selectively etched GaN using a spin-coating method. With the embedded silica nanospheres structures, we achieved a smaller reverse leakage current due to the selective defect blocking-induced crystal quality improvement. Moreover, the reflectance spectra show strong reflectance modulations due to the different refractive indices between the GaN and silica nanospheres. By using confocal scanning electroluminescence microscopy, a strong light emission from silica nanospheres demonstrates that the silica nanospheres acted as a reflector. We found that the optimized embedded silica nanospheres structure, whose the average size of the etched pits was about 3.5 μm and EPD was 3 x 10(7) cm(-2), could enhance light output power by a factor of 2.23 due to enhanced the probability of light scattering at silica nanospheres.
我们报道了嵌入二氧化硅纳米球对提高氮化铟镓/氮化镓发光二极管（LED）性能的影响。采用旋涂法将二氧化硅纳米球涂覆在选择性蚀刻的氮化镓上。通过嵌入二氧化硅纳米球结构，由于选择性缺陷阻挡导致晶体质量提高，我们实现了更小的反向漏电流。此外，由于氮化镓和二氧化硅纳米球之间的折射率不同，反射光谱显示出强烈的反射调制。通过使用共聚焦扫描电致发光显微镜，二氧化硅纳米球发出的强光表明二氧化硅纳米球起到了反射器的作用。我们发现，优化后的嵌入二氧化硅纳米球结构，其蚀刻坑的平均尺寸约为3.5μm，位错密度为3×10⁷ cm⁻²，由于提高了二氧化硅纳米球处的光散射概率，可使光输出功率提高2.23倍。
