High-Sensitivity Visible-Blind AlGaN Photodiodes and Photodiode Arrays

Abstract

Visible-blind UV cameras based on a 32 × 32 array of backside-illuminated GaN/AlGaN p-i-n photodiodes have been successfully demonstrated. The photodiode arrays were hybridized to silicon readout integrated circuits (ROICs) using In bump bonds. Output from the UV cameras were recorded at room temperature at frame rates of 30−240 Hz. These new visible-blind digital cameras are sensitive to radiation from 285−365 nm in the UV spectral region.

Photocurrent spectroscopy investigation of deep level defects in Mg-doped GaN and Mg-doped AlxGa1−xN (0.20<x<0.52)

“…[2][3][4] Despite significant progress in material growth and device performance, pervasive challenges related to structural and electronic defects have not yet been overcome. [5][6][7] One of the fundamental limitations in developing III-nitride based optoelectronic devices is the inability to achieve sufficient carrier concentrations for effective device performance.…”

Back-illuminated solar-blind photodetectors for imaging applications

“…Despite these technical difficulties, several groups have achieved limited success in demonstrating visible and solar-blind focal plane array (FPA) cameras of various sizes. 4,5,6,7 In this paper we present the results of a 320 x 256 AlGaN based solar-blind focal plane array camera, and then discuss future improvements that could improve the imaging performance. We start by looking at the I-V and photoresponse characteristics of single 25 µm x 25 µm pixel AlGaN-based solar-blind photodetectors.…”

Nitride-based photodetectors: from visible to X-ray monitoring

“…Thanks to their direct bandgap energy, Al x Ga 1−x N photodetectors have demonstrated in the last decade visible and solar-radiation rejection ratios higher than four orders of magnitude as well as high detectivities (D * = 6.3×10 13 cm Hz 1/2 W −1 ), which have made them very much adequate for near-and mid-UV applications [1,2]. Nowadays, their intended development in fields such as biomedicine, astronomy, photolithography, and combustion monitoring requires that the operation range broadens, covering the visible, vacuum-UV (VUV), and soft X-ray regions.…”