Title :
InGaN–GaN MQW Metal–Semiconductor–Metal Photodiodes With Semi-Insulating Mg-Doped GaN Cap Layers
Author :
Yu, C.L. ; Chuang, R.W. ; Chang, S.J. ; Chang, P.C. ; Lee, K.H. ; Lin, J.C.
Author_Institution :
Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan
fDate :
6/1/2007 12:00:00 AM
Abstract :
InGaN-GaN multiple-quantum-well metal-semiconductor-metal photodiodes (PDs) with in situ grown 40-nm-thick unactivated semi-insulating Mg-doped GaN cap layer were successfully fabricated. The dark leakage current of this PD was comparably much smaller than that of conventional PD without the semi-insulating layer, because of a thicker and higher potential barrier of semi-insulating cap layer, and also a smaller number of surface states involved. For the PDs with the semi-insulating Mg-doped GaN cap layers, the responsivity at 380nm was 0.372A/W when biasing at 5 V. In short, incorporating a semi-insulating Mg-doped GaN cap layer into the PDs beneficially leads to the suppression of dark current and a corresponding improvement in the ultraviolet-to-visible rejection ratio
Keywords :
III-V semiconductors; dark conductivity; gallium compounds; indium compounds; magnesium; metal-semiconductor-metal structures; optical fabrication; photodiodes; semiconductor doping; surface states; wide band gap semiconductors; 380 nm; 5 V; GaN:Mg; InGaN-GaN; InGaN-GaN MQW metal-semiconductor-metal photodiodes; Mg-doped GaN cap layers; dark leakage current; surface states; ultraviolet-to-visible rejection ratio; Commercialization; Dark current; Diode lasers; Gallium nitride; Helium; Leakage current; Light emitting diodes; Object detection; Photodiodes; Quantum well devices; InGaN–GaN multiple-quantum-well (MQW); Mg-doped GaN; photodiodes (PDs);
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2007.897432
