Saturation of the junction voltage in GaN-based laser diodes
Saturation of the junction voltage in GaN-based laser diodes
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DOI：
10.1063/1.4804384
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发表时间：
2013-05
影响因子：
4
通讯作者：
M. Feng;Jianping Liu;S. Zhang;Zhongxin Liu;D. Jiang;Z. Li;Feng Wang;Deyao Li;Li Zhang;Hushan Wang;H. Yang
中科院分区：
文献类型：
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作者：
M. Feng;Jianping Liu;S. Zhang;Zhongxin Liu;D. Jiang;Z. Li;Feng Wang;Deyao Li;Li Zhang;Hushan Wang;H. Yang
研究了GaN基半导体激光器结电压的饱和现象。结果表明，在I（dV/dI）-I曲线中，在激光跃迁的上方存在一个凸起，而不是GaAs基LD的凹陷。I（dV/dI）-I曲线中的凸起随着激光阈值沿着向更高的电流移动。使用考虑双极导电和由于有源区载流子限制较差而导致电子溢出到p-AlGaN包层的模型来解释这种异常。通过拟合阈值电流I（dV/dI）-I曲线，得到GaN基LD的特征温度。此外，研究发现GaN基半导体激光器具有非线性串联电阻特性，这可能是由于电子溢出到p-AlGaN包层和Mg受主激活增强所致。
Saturation of the junction voltage in GaN-based laser diodes (LDs) is studied. It is found that there is a bump above the lasing transition in the I(dV/dI)-I curve, instead of a dip as that for GaAs-based LDs. The bump in I(dV/dI)-I curve moves to higher currents along with the lasing threshold. A model considering ambipolar conduction and electron overflow into p-AlGaN cladding layer due to poor carrier confinement in active region is used to explain the anomaly. The characteristic temperature of GaN-based LD is obtained by fitting threshold currents determined from I(dV/dI)-I curves. Moreover, it is found that GaN-based LDs show characteristics with a nonlinear series resistance, which may be due to the electron overflow into p-AlGaN cladding layer and the enhanced activation of Mg acceptors.