An Anomalous Gain Mechanism in GaN Schottky Barrier Ultraviolet Photodetectors
ZHAO De-Gang1, JIANG De-Sheng1, LIU Zong-Shun1, ZHU Jian-Jun1, WANG Hui1, ZHANG Shu-Ming1, YANG Hui1,2
1State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 1000832Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215125
An Anomalous Gain Mechanism in GaN Schottky Barrier Ultraviolet Photodetectors
ZHAO De-Gang1, JIANG De-Sheng1, LIU Zong-Shun1, ZHU Jian-Jun1, WANG Hui1, ZHANG Shu-Ming1, YANG Hui1,2
1State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 1000832Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215125
摘要The gain mechanism in GaN Schottky barrier ultraviolet photodetectors is investigated by focused light beam. When the incident light illuminates the central region of the Schottky contact electrode, the responsivity changes very little with the increase of reverse bias voltage. However, when the incident light illuminates the edge region of the electrode, the responsivity increases remarkably with the increase of reverse bias voltage, and the corresponding quantum efficiency could be even higher than 100%. It is proposed that the surface states near the edge of the electrode may lead to a reduction of effective Schottky barrier height and an enhancement of electron injection, resulting in the anomalous gain.
Abstract：The gain mechanism in GaN Schottky barrier ultraviolet photodetectors is investigated by focused light beam. When the incident light illuminates the central region of the Schottky contact electrode, the responsivity changes very little with the increase of reverse bias voltage. However, when the incident light illuminates the edge region of the electrode, the responsivity increases remarkably with the increase of reverse bias voltage, and the corresponding quantum efficiency could be even higher than 100%. It is proposed that the surface states near the edge of the electrode may lead to a reduction of effective Schottky barrier height and an enhancement of electron injection, resulting in the anomalous gain.
ZHAO De-Gang;JIANG De-Sheng;LIU Zong-Shun;ZHU Jian-Jun;WANG Hui;ZHANG Shu-Ming;YANG Hui;. An Anomalous Gain Mechanism in GaN Schottky Barrier Ultraviolet Photodetectors[J]. 中国物理快报, 2009, 26(5): 58501-058501.
ZHAO De-Gang, JIANG De-Sheng, LIU Zong-Shun, ZHU Jian-Jun, WANG Hui, ZHANG Shu-Ming, YANG Hui,. An Anomalous Gain Mechanism in GaN Schottky Barrier Ultraviolet Photodetectors. Chin. Phys. Lett., 2009, 26(5): 58501-058501.
[1] Chen Q, Yang J W, Osinsky A, Gangopadhyay S, Lim B, AnwarM Z, Khan M A, Kuksenkov D and Temkin H 1997 Appl. Phys. Lett. 70 2277 [2] Katz O, Garber V, Meyler B, Bahir G, and Salzman J 2001 Appl. Phys. Lett. 79 1417 [3] Carrano J C, Gruowski P A, Eiting S J, Dupuis R D andCampbell J C 1997 Appl. Phys. Lett. 70 1992 [4] Carrano J C, Li T, Grudowski P A, Eiting C J, Dupuis R Dand Campbell J C 1998 J. Appl. Phys. 83 6148 [5] Zhang S K, Wang W B, Shtau I, Yun F, He L, Morkoc H, ZhouX, Tamargo M and Alfano R R 2002 Appl. Phys. Lett. 814862 [6] Lee M L, Sheu J K, Lai W C, Su Y K, Chang S J, Kao C J,Tun C J, Chen M G, Chang W H, Chi G C and Tsai J M 2003 J.Appl. Phys. 94 1753 [7] Van Hove J M, Hickman R, Klaassen J J, Chow P P and RudenP P 1997 Appl. Phys. Lett. 70 2282 [8] Osinsky A, Gangopadhyay S, Gaska R, Williams B, Khan M A,Kuksenkov D and Temkin H 1997 Appl. Phys. Lett. 71 2334 [9] Collins C J, Chowdhury U, Wong M M, Yang B, Beck A L,Dupuis R D and Campbell J C 2002 Appl. Phys. Lett. 803754 [10] Monroy E, Calle F, Munoz E and Omnes F 1999 Appl.Phys. Lett. 74 3401 [11] McClintock R, Mayes K, Yasan A, Shiell D, Kung P, andRazeghi M 2005 Appl. Phys. Lett. 86 011117 [12] Sze S M 1981 Physics of Semiconductor Devices 2ndedn (New York: Wiley) [13] Zhang X, Kung P, Walker D, Biotrowski J, Rogalski A,Sazier A and Razeghi M 1995 Appl. Phys. Lett. 67 2028 [14] The freeware program 'AMPS-1D' is supplied by theElectronic Materials and Processing Research Laboratory of PennState University, USA. [15] Li N, Zhao D G and Yang H 2004 Solid State Commun. 132 701 [16] Brown J D, Yu Zhonghai, Matthews J, Harney S, Boney J,Schetzina J F, Benson J D, Dang K W, Terrill C, Nohava Thomas, YangWei and Krishnankutty Subash 1999 MRS Internet J. NitrideSemicond. Res. 4 9 [17] Sabuktagin S, Moon Y T, Dogan S, Baski A A, and Morkoc H2006 IEEE Electron Device Lett. 67 211 [18] Katz O, Bahir G, and Salzman J 2004 Appl. Phys.Lett. 84 4092
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