Title :
Solar-blind AlGaN-based p-i-n photodiodes with low dark current and high detectivity
Author :
Biyikli, N. ; Kimukin, I. ; Aytur, O. ; Ozbay, E.
Author_Institution :
Dept. of Electr. & Electron. Eng., Bilkent Univ., Ankara, Turkey
fDate :
7/1/2004 12:00:00 AM
Abstract :
We report solar-blind AlxGa1-xN-based heterojunction p-i-n photodiodes with low dark current and high detectivity. After the p+ GaN cap layer was recess etched, measured dark current was below 3 fA for reverse bias values up to 6 V. The device responsivity increased with reverse bias and reached 0.11 A/W at 261 nm under 10-V reverse bias. The detectors exhibited a cutoff around 283 nm, and a visible rejection of four orders of magnitude at zero bias. Low dark current values led to a high differential resistance of 9.52×1015 Ω. The thermally limited detectivity of the devices was calculated as 4.9×1014 cm·Hz12/W-1.
Keywords :
III-V semiconductors; aluminium compounds; etching; gallium compounds; p-i-n photodiodes; semiconductor heterojunctions; wide band gap semiconductors; AlGaN; dark current; detectivity; etching; p-i-n photodiodes; solar-blind AlGaN-based heterojunction; Chemical vapor deposition; Current measurement; Dark current; Detectors; Etching; Fabrication; Gallium nitride; Ohmic contacts; PIN photodiodes; Photodetectors;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2004.829526