具有电流阻挡层的不同GaN基LED的光电特性

摘要

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.%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.