High-performance solar-blind AlGaN photodetectors

Date
2005
Authors
Özbay, Ekmel
Tut, Turgut
Bıyıklı, N.
Advisor
Instructor
Source Title
Proceedings of SPIE Vol. 5732, Quantum Sensing and Nanophotonic Devices II
Print ISSN
1605-7422
Electronic ISSN
Publisher
SPIE
Volume
5732
Issue
Pages
375 - 388
Language
English
Type
Conference Paper
Journal Title
Journal ISSN
Volume Title
Abstract

Design, fabrication, and characterization of high-performance Al xGa1-xN-based photodetectors for solar-blind applications are reported. AlxGa1-xN heterostructures were designed for Schottky, p-i-n, and metal-semiconductor-metal (MSM) photodiodes. The solar-blind photodiode samples were fabricated using a microwave compatible fabrication process. The resulting devices exhibited extremely low dark currents. Below 3 fA leakage currents at 6 V and 12 V reverse bias were measured on p-i-n and Schottky photodiode samples respectively. The excellent current-voltage (I-V) characteristics led to a detectivity performance of 4.9×1014 cmHz1/2W-1. The MSM devices exhibited photoconductive gain, while Schottky and p-i-n samples displayed 0.15 A/W and 0.11 A/W peak responsivity values at 267 nm and 261 nm respectively. All samples displayed true solar-blind response with cut-off wavelengths smaller than 280 nm. A visible rejection of 4×104 was achieved with Schottky detector samples. High speed measurements at 267 nm resulted in fast pulse responses with >GHz bandwidths. The fastest devices were MSM photodiodes with a maximum 3-dB bandwidth of 5.4 GHz.

Course
Other identifiers
Book Title
Keywords
AlGaN, Detectivity, Heterostructure, High-speed, MSM, Photodetector, Schottky, Solar-blind, UV, Aluminum nitride, Characterization, Fabrication, Gallium nitride, Heterojunctions, Leakage currents, Photoconducting materials, Photodiodes, Photomultipliers, Schottky barrier diodes, Ternary systems, Metal-semiconductor-metal (MSM), P-i-n
Citation
Published Version (Please cite this version)