GaN基光发射二极管中深能级研究

利用深能级瞬态谱 (DLTS)仪对 Si C衬底上 Ga N基光发射二极管 (LED)中 n-In0 .2 5Ga0 .75N层的深能级进行了研究。在 77K到 3 0 0 K的温度扫描范围内只测量到一个 DLTS峰。该 DLTS峰在反向偏压为 3 V时有一极大值 ,说明 n-In0 .2 5Ga0 .75N层此时全部被耗尽。改变测量的率窗 ,得到该深能级在导带下 0 .2 4e V处 ,浓度为 2 .2 % ND,俘获截面为 1 .93× 1 0 - 1 5cm2。在 Ga N材料中 ,其他小组也报道了此位置上的深能级结果。结合文中的工作 ,该深能级可能和 n-In0 .2 5Ga0 .75N层中的线位错有关。

Study of the Deep Level in GaN-based Light Emitting Diode

The deep level in n In 0.25 Ga 0.75 N layer of GaN based light emitting diode (LED) on SiC substrate was studied using deep level transient spectroscopy (DLTS). In the scanning range of temperature 77 K～300 K, only one deep level could be measured. At the reverse bias of 3 V, the DLTS peak amplitude reaches a maximum, which indicates that n In 0.25 Ga 0.75 N layer is depleted completely. With the rate window changed, this deep level was determined to position at E C 0.24 eV. At the same time, its concentration and capture cross section were calculated as 2.2% N D and 1.93×10 -15 cm 2. In the case of GaN, other groups also reported the deep level at this position. According to our work, this deep level in n In 0.25 Ga 0.75 N layer may be associated with the line dislocation.