16 × 16 Solar-Blind UV Detector Based on β-Ga<sub>2</sub>O<sub>3</sub> Sensors
Gao-Hui Shen, Zeng Liu, Maolin Zhang, Yufeng Guo, Weihua Tang
Abstract
In this work, a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${16}\times {16}$ </tex-math></inline-formula> Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> photodetector array is introduced. The Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> thin film was deposited on <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${c}$ </tex-math></inline-formula> -sapphire substrate by employing metal-organic chemical vapor deposition, and the array device was constructed via UV photolithography, lift-off and electron-beam evaporation techniques. The high rejection ratio of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${8}\times {10} ^{{3}}$ </tex-math></inline-formula> indicate good wavelength selectivity. The photodetector displayed responsivity of 60.7 A W <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> , specific detectivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${2}.{2}\times {10} ^{{14}}$ </tex-math></inline-formula> cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sqrt {\textit {Hz}}\,\,\text{W}^{-{1}}$ </tex-math></inline-formula> (Jones), external quantum efficiency of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${3}\times {10} ^{{4}}$ </tex-math></inline-formula> %, linear dynamic region of 120.34 dB, respectively. Excited by a laser, the photodetector had a rise time of 6 ms and a decay time of 48 ms, suggesting a fast response ability for tracing light signal. For the 256 pixels in this array, the dark current locates from 2 pA to 4 pA, and shown no disparity. More than 75% of the units have a maximum standard deviation of less than 10%. This work could show a guidance for advancing the solar-blind UV sensing devices and further applications.