High-performance self-powered UV-Vis-NIR photodetectors based on horizontally aligned GaN microwire array/Si heterojunctions. Issue 44 (27th October 2017)

• Record Type: Journal Article
• Authors: Song, Weidong; Wang, Xingfu; Chen, Hang; Guo, Dexiao; Qi, Mingyue; Wang, Hu; Luo, Xingjun; Luo, Xiao; Li, Guang; Li, Shuti
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 44(2017)
• Page Start: 11551
• Page End: 11558
• Publication Date: 2017-10-27
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7tc04184e
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : High-performance self-powered photodetectors based on GaN microwire array/Si heterojunctions show a broadband photoresponse with high EQE, responsivity and detectivity at zero bias. Abstract : Considering their reduced size and weight, low cost and portability, self-powered photodetectors that can be functioned independently of an external power supply are extremely important for developing future sensor networks and Internets of Things. Here, we present a self-powered photodetector with a broadband wavelength photoresponse from the ultraviolet to near-infrared region based on GaN microwire array/Si heterojunctions. Due to the highly efficient separation of photogenerated charge carriers, the photodetector shows ultrahigh EQE, responsivity and detectivity, reaching up to 71%, 4.7 × 10 2 mA W −1 and 9.5 × 10 12 Jones, respectively, at zero bias in the 320–850 nm range. A fast response is observed with rise/decay times as low as 2/2 ms. The LDR values are over 80 dB. The performance characteristics are competitive with commercially available biased photodetectors and other reported heterojunction self-powered broadband photodetectors in the literature. In addition, a binary photoresponse is observed under small bias voltages. The heterostructures are fabricated by directly heteroepitaxially growing GaN microwires on patterned Si, enabling large-area device applications, and stand out from low-dimensional semiconductor photodetection systems. The overall high performance coupled with large-scale production makes GaN microwire array/Si heterojunctions promising for practical self-powered broadband photodetectors.