Electrical characteristics of InGaN/GaN light-emitting diodes grown on GaN and sapphire substrates
Electrical characteristics of InGaN/GaN light-emitting diodes grown on GaN and sapphire substrates
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DOI：
10.1063/1.1767280
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发表时间：
2004-07-05
影响因子：
4
通讯作者：
Yan, CH
中科院分区：
文献类型：
--
作者：
Cao, XA;Teetsov, JM;Yan, CH
我们报道了生长在蓝宝石和独立GaN衬底上的InGaN/GaN多量子阱发光二极管（LED）的电学特性。由于缺陷减少，在同质外延生长的LED的隧穿电流显着抑制和扩散复合电流占主导地位，在中间正向偏压。随温度变化的测量结果表明，剩余的反向电流起源于载流子产生和隧道深能级陷阱。相比之下，蓝宝石上的LED在宽范围的施加偏压上表现出主导的隧穿特性。使用导电原子力显微镜的纳米级电学表征揭示了V缺陷处的高度局部化电流，表明相关的位错是电活性的，并且可能是异质外延生长的LED中的高漏电流的原因。(C)2004年，美国物理学会。
We report on the electrical characteristics of InGaN/GaN multiple-quantum-well light-emitting diodes (LEDs) grown on sapphire and free-standing GaN substrates. As a result of defect reduction, the tunneling current in the homoepitaxially grown LED was remarkably suppressed and diffusion-recombination current dominated at intermediate forward bias. Temperature-dependent measurements showed that the remaining reverse current originated from carrier generation and tunneling associated with deep-level traps. In contrast, the LED on sapphire exhibited dominant tunneling characteristics over a wide range of applied bias. Nanoscale electrical characterization using conductive atomic force microscopy revealed highly localized currents at V-defects, indicating that the associated dislocations are electrically active and likely responsible for the high leakage current in the heteroepitaxially grown LED. (C) 2004 American Institute of Physics.