研究对比了InGaN/GaN多量子阱发光二极管中p电极下的不同SiO2电流阻挡层的光电特性。 6种样品被分为3组: 普通表面、表面粗化、表面粗化+边墙腐蚀。每组都有两种结构, 一种具有电流阻挡层, 另一种没有电流阻挡层。每组中, 具有电流阻挡层的LED在20 mA下的正向电压分别为3.156, 3.282, 3.284 V, 略高于不含电流阻挡层的样品(Vf=3.105, 3.205, 3.210 V). 但是, 具有电流阻挡层的LED的光效和光功率要优于无电流阻挡层的器件, 在20 mA下的光功率分别提高了10.20%、12.19%和11.49%。这些性能的提升都要归功于电流阻挡层良好的电流扩展效应, 同时电流阻挡层还可以减小p电极下的寄生光吸收。

InGaN/GaN multiple-quantum well (MQW) light-emitting diodes (LEDs) were fabricated, in which a SiO2 current blocking layer (CBL) was inserted underneath the p-pad electrode. Samples were divided into three groups: normal surface, surface roughing, and surface roughing plus side wall etching. Each group had two different structure devices: with and without CBL. In each group, the voltage Vf at 20 mA for the LEDs with a CBL (Vf=3.156, 3.282, 3.284 V) were slightly higher than those of without CBL (Vf=3.105, 3.205, 3.210 V). However, the luminous efficiency and the light-output power of the LEDs with CBL were better than those without CBL. At 20 mA current, the output power of the LEDs with a CBL increase 10.20%, 12.19%, 11.49% compared with those without CBL. It is due to the current spreading effect in CBL devices. The CBL can also reduce parasitic optical absorption in the p-pad electrode.