High Photo-Responsivity Deep-UV Detector Based on Binary SnO₂-Ga₂O₃ Compound Nanowires Array

Abstract

Deep-UV photodetectors (DUV PDs) have displayed huge potentials in both military and civilian applications due to the low background noise interference. In this work, the binary SnO2-Ga2O3 compound nanowires array with excellent photo-response properties had been successfully fabricated by using low-pressure chemical vapor deposition (LP-CVD) with the Ga2O3, SnO2, and carbon powders as reaction sources. The diameter of compound nanowires is approximately 135 nm for binary oxide SnO2-Ga2O3. The SnO2-Ga2O3 nanowires deep-UV photodetector achieved large photo-responsivity ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$R$ </tex-math></inline-formula> ) of 2.2 A/W under illumination with a light intensity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$162~\mu \text{W}$ </tex-math></inline-formula> /cm2 at 5 V, with the high photocurrent of dozens of microamperes. The high photo-response of compound nanowires array may well be owing to the high-quality of crystal and the large exposed area when illuminated; which is the main advantage of nanowire structure. In a word, this work could provide a feasible pathway in boosting the development of nanowire-based DUV PDs based on wide band gap semiconductors, along with promised photo-response characteristics.