氮化銦鎵-氮化鎵之多層量子井藍光發光二極體之電容量測

Abstract

我們以電容量測的方式來討論氮化銦鎵-氮化鎵多層量子井藍光發光二極體的缺陷。在量子井結構附近，我們發現一個缺陷，能階位置約為電導帶下100 ，濃度在1018 以上，捕捉截面積為10-20 。當實驗溫度降低至110 時，於0~2.5 處之電容呈現明顯變化，我們認為與缺陷之空間分佈有關。另外一方面，在頻率大於8 ，會出現累積電容和負電容，原因可能是有很大之淨電感存在，淨值為31~45 。除了外部線路所貢獻之串聯電感值為5.4 外，主要皆由元件本身所貢獻。我們懷疑造成元件存有如此大寄生串聯電感之原因，可能是元件本身之量子井結構所造成。

We have studied the electrical properties of an InGaN/GaN multi-quantum-well blue light-emitting diode (LED) by capacitance and admittance measurements. A defect with an energy level of 100 and capture cross-section of was found to locate in the region of quantum-well. Additionally, we have also found a large value of inductance in the device, which conceivably responses for the observed accumulation capacitance and the large negative capacitance at high frequencies. Its value ranges from 31 to 45μH. Since the external wire can only contribute a value of 5.4μH for this device, we believe such a large value of inductance is closely related to the quantum-well structure in this device.