A Study of Efficiency Droop Phenomenon in GaN-Based Laser Diodes before Lasing

Mei-Xin Feng; Qian Sun; Jian-Ping Liu; Zeng-Cheng Li; Yu Zhou; Shu-Ming Zhang; Hui Yang

doi:10.3390/ma10050482

A Study of Efficiency Droop Phenomenon in GaN-Based Laser Diodes before Lasing

Materials (Basel). 2017 Apr 30;10(5):482. doi: 10.3390/ma10050482.

Authors

Mei-Xin Feng^{1

2}, Qian Sun^{3

4}, Jian-Ping Liu^{5

6}, Zeng-Cheng Li^{7

8}, Yu Zhou^{9

10}, Shu-Ming Zhang^{11

12}, Hui Yang^{13

14}

Affiliations

¹ The Key Laboratory of Nanodevices and Applications, Chinese Academy of Sciences, Suzhou 215123, China. mxfeng2011@sinano.ac.cn.
² Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China. mxfeng2011@sinano.ac.cn.
³ The Key Laboratory of Nanodevices and Applications, Chinese Academy of Sciences, Suzhou 215123, China. qsun2011@sinano.ac.cn.
⁴ Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China. qsun2011@sinano.ac.cn.
⁵ The Key Laboratory of Nanodevices and Applications, Chinese Academy of Sciences, Suzhou 215123, China. jpliu2010@sinano.ac.cn.
⁶ Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China. jpliu2010@sinano.ac.cn.
⁷ The Key Laboratory of Nanodevices and Applications, Chinese Academy of Sciences, Suzhou 215123, China. zcli2011@sinano.ac.cn.
⁸ Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China. zcli2011@sinano.ac.cn.
⁹ The Key Laboratory of Nanodevices and Applications, Chinese Academy of Sciences, Suzhou 215123, China. yzhou2008@sinano.ac.cn.
¹⁰ Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China. yzhou2008@sinano.ac.cn.
¹¹ The Key Laboratory of Nanodevices and Applications, Chinese Academy of Sciences, Suzhou 215123, China. smzhang2010@sinano.ac.cn.
¹² Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China. smzhang2010@sinano.ac.cn.
¹³ The Key Laboratory of Nanodevices and Applications, Chinese Academy of Sciences, Suzhou 215123, China. hyang2006@sinano.ac.cn.
¹⁴ Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China. hyang2006@sinano.ac.cn.

Abstract

Carrier recombination behavior in c-plane GaN-based laser diodes (LDs) is numerically investigated by using the commercial software LASTIP. It is found that efficiency droop phenomenon does exist in GaN-based LDs before lasing, which is confirmed by experimental results. However, the current density corresponding to the peak efficiency of GaN-based LDs before lasing, J_max, is nearly 40 A/cm², which is much lower than that reported by other studies. The reported J_max, measured from the cavity facet side is modulated by the absorption of quantum wells, which shifts the J_max to a higher value. In addition, the currents due to various recombinations are calculated. It is found that Auger recombination affects the threshold current greatly, but it only plays a small role at high current injection levels.

Keywords: Auger recombination; efficiency droop; laser diodes; stimulated emission.