中国物理B ›› 2021, Vol. 30 ›› Issue (11): 117302-117302.doi: 10.1088/1674-1056/abfa07

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Abnormal phenomenon of source-drain current of AlGaN/GaN heterostructure device under UV/visible light irradiation

Yue-Bo Liu(柳月波)1, Jun-Yu Shen(沈俊宇)1, Jie-Ying Xing(邢洁莹)1, Wan-Qing Yao(姚婉青)1, Hong-Hui Liu(刘红辉)1, Ya-Qiong Dai(戴雅琼)1, Long-Kun Yang(杨隆坤)1, Feng-Ge Wang(王风格)1, Yuan Ren(任远)1, Min-Jie Zhang(张敏杰)1, Zhi-Sheng Wu(吴志盛)1,2, Yang Liu(刘扬)1,2, and Bai-Jun Zhang(张佰君)1,2,†   

  1. 1 School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510006, China;
    2 State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
  • 收稿日期:2021-03-03 修回日期:2021-04-12 接受日期:2021-04-21 出版日期:2021-10-13 发布日期:2021-10-13
  • 通讯作者: Bai-Jun Zhang E-mail:zhbaij@mail.sysu.edu.cn
  • 基金资助:
    Project supported by Key-Area Research and Development Program of Guangdong Province, China (Grant Nos. 2019B010132001 and 2019B010132003), the Joint Funding of the National Natural Science Foundation of China (NSFC) & the Macao Science and Technology Development Fund (FDCT) of China (Grant No. 62061160368), the National Key Research and Development Program of China (Grant Nos. 2016YFB0400105 and 2017YFB0403001), and the Zhuhai Key Technology Laboratory of Wide Bandgap Semiconductor Power Electronics, Sun Yat-sen University, China (Grant No. 20167612042080001).

Abnormal phenomenon of source-drain current of AlGaN/GaN heterostructure device under UV/visible light irradiation

Yue-Bo Liu(柳月波)1, Jun-Yu Shen(沈俊宇)1, Jie-Ying Xing(邢洁莹)1, Wan-Qing Yao(姚婉青)1, Hong-Hui Liu(刘红辉)1, Ya-Qiong Dai(戴雅琼)1, Long-Kun Yang(杨隆坤)1, Feng-Ge Wang(王风格)1, Yuan Ren(任远)1, Min-Jie Zhang(张敏杰)1, Zhi-Sheng Wu(吴志盛)1,2, Yang Liu(刘扬)1,2, and Bai-Jun Zhang(张佰君)1,2,†   

  1. 1 School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510006, China;
    2 State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
  • Received:2021-03-03 Revised:2021-04-12 Accepted:2021-04-21 Online:2021-10-13 Published:2021-10-13
  • Contact: Bai-Jun Zhang E-mail:zhbaij@mail.sysu.edu.cn
  • Supported by:
    Project supported by Key-Area Research and Development Program of Guangdong Province, China (Grant Nos. 2019B010132001 and 2019B010132003), the Joint Funding of the National Natural Science Foundation of China (NSFC) & the Macao Science and Technology Development Fund (FDCT) of China (Grant No. 62061160368), the National Key Research and Development Program of China (Grant Nos. 2016YFB0400105 and 2017YFB0403001), and the Zhuhai Key Technology Laboratory of Wide Bandgap Semiconductor Power Electronics, Sun Yat-sen University, China (Grant No. 20167612042080001).

摘要: We report an abnormal phenomenon that the source-drain current (ID) of AlGaN/GaN heterostructure devices decreases under visible light irradiation. When the incident light wavelength is 390 nm, the photon energy is less than the band gaps of GaN and AlGaN whereas it can causes an increase of ID. Based on the UV light irradiation, a decrease of ID can still be observed when turning on the visible light. We speculate that this abnormal phenomenon is related to the surface barrier height, the unionized donor-like surface states below the surface Fermi level and the ionized donor-like surface states above the surface Fermi level. For visible light, its photon energy is less than the surface barrier height of the AlGaN layer. The electrons bound in the donor-like surface states below the Fermi level are excited and trapped by the ionized donor-like surface states between the Fermi level and the conduction band of AlGaN. The electrons trapped in ionized donor-like surface states show a long relaxation time, and the newly ionized donor-like surface states below the surface Fermi level are filled with electrons from the two-dimensional electron gas (2DEG) channel at AlGaN/GaN interface, which causes the decrease of ID. For the UV light, when its photon energy is larger than the surface barrier height of the AlGaN layer, electrons in the donor-like surface states below the Fermi level are excited to the conduction band and then drift into the 2DEG channel quickly, which cause the increase of ID.

关键词: AlGaN/GaN heterostructure, two-dimensional electron gas (2DEG), surface states, irradiation

Abstract: We report an abnormal phenomenon that the source-drain current (ID) of AlGaN/GaN heterostructure devices decreases under visible light irradiation. When the incident light wavelength is 390 nm, the photon energy is less than the band gaps of GaN and AlGaN whereas it can causes an increase of ID. Based on the UV light irradiation, a decrease of ID can still be observed when turning on the visible light. We speculate that this abnormal phenomenon is related to the surface barrier height, the unionized donor-like surface states below the surface Fermi level and the ionized donor-like surface states above the surface Fermi level. For visible light, its photon energy is less than the surface barrier height of the AlGaN layer. The electrons bound in the donor-like surface states below the Fermi level are excited and trapped by the ionized donor-like surface states between the Fermi level and the conduction band of AlGaN. The electrons trapped in ionized donor-like surface states show a long relaxation time, and the newly ionized donor-like surface states below the surface Fermi level are filled with electrons from the two-dimensional electron gas (2DEG) channel at AlGaN/GaN interface, which causes the decrease of ID. For the UV light, when its photon energy is larger than the surface barrier height of the AlGaN layer, electrons in the donor-like surface states below the Fermi level are excited to the conduction band and then drift into the 2DEG channel quickly, which cause the increase of ID.

Key words: AlGaN/GaN heterostructure, two-dimensional electron gas (2DEG), surface states, irradiation

中图分类号:  (III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions)

  • 73.40.Kp
73.20.At (Surface states, band structure, electron density of states) 61.80.Ba (Ultraviolet, visible, and infrared radiation effects (including laser radiation))