Ultrafast response solar-blind UV sensor based on ZnGa2O4 nanowire bridge arrays

Abstract

In optoelectronic devices and deep UV photodetectors, there is an urgent need for solar-blind photodetectors with a fast response time. Spinel ZnGa 2 O 4 is a wide-bandgap metal-oxide direct-gap semiconductor (4.4–5.2 eV, UV band for 100–280 nm) with outstanding optical and electrical properties, making it the best choice for solar-blind photodetectors. In this work, the ZnGa 2 O 4 lateral nanowire bridge arrays were speedily manufactured on an insulating SiO 2 /Si substrate with a simplified specific low-cost CVD process with Au arrays catalyst. A thin film of ZnGa 2 O 4 nanowire bridge arrays was synthesized in 3 min, implying a high potential for the fast development of ZnGa 2 O 4 nanowire bridge arrays and their application in the future solar-blind photodetectors. Furthermore, a solar-blind photodetector using MSM (Metal-Semiconductor-Metal) ZnGa 2 O 4 bridge arrays with exceptional performance was developed here, with a rise time of similar to 0.067 s, an I dark of 0.041 nA, and a light-dark ratio 3.3 × 10 2 . Meanwhile, the response time of the nanowire arrays photodetector was 10 times faster than that of the nanowire networks photodetector prepared by the same method. Our work provided inspiration for the manufacture of high-performance solar-blind photodetectors. • ZnGa 2 O 4 nanowire bridge arrays were grown by CVD method and used to fabricate a MSM solar-blind UV photodetectors. • The growth method is fast, low cost and capable of patterned growth. • The ZnGa 2 O 4 nanowire bridge array photodetector has a larger photocurrent and a faster response speed than the nanowire photodetector grown by the same method.