Fabrication of a fine-pattern flexible nanowire photodetector by shadow mask

Abstract

F.NM01.10.09 Late News: Fabrication of a Fine-Pattern Flexible Nanowire Photodetector by Shadow Mask Abstract Body: Recently, ultraviolet photodetectors (UVPDs) have been used on largescale applications such as environmental monitoring, flame detection, spacecommunication, biomedical applications, pharmaceutical, and chemical analysis.Besides, advances in internet technologies such as the internet of things (IoT) endorsethe integration of sensors more rapidly in every aspect of our lives. This trend demandsthe fabrication of smaller, lighter, less complicated, and low power devices. Therefore,designing low cost, self-powered, highly sensitive, Óexible UVPD nanodevices arebecoming a hot research area for near future optoelectronics. Silicon carbide (SiC), awide bandgap semiconductor, is an excellent contender to fulfill those expectations. Inaddition to having characteristics of one-dimensional nanostructure such as highsurface to volume ratio, high crystalline quality, SiC nanowires also possess superiormaterial attributes like high breakdown voltage, high thermal conductivity, high driftvelocity, excellent chemical and physical stability. In this study, we propose a very cost-effective, flexible, self-powered single SiC nanowire ultraviolet photodetector (SiCNWUVPD) fabricated on a polyvinylchloride (PVC) substrate. The self-powered flexibleSiCNW-UVPD was fabricated via a commercially available transmission electronmicroscopy (TEM) grid (physical mask) and a sputter coater system. Gold (Au)electrodes of 110 µm x 110 µm and a gap of 4 µm were successfully achieved withoutthe use of complicated and expensive methods like photolithography. Two-probephotocurrent-time (I-t) and I-V measurements were performed to revealphotoresponse characteristics such as the photo-to-dark current ratio (PDCR),sensitivity, and responsivity under 254 nm wavelength UV light at 0 V bias. A shallowdark current around 0.087 pA and a good PDCR value of 18 are obtained. Moreover,sensitivity and responsivity values are calculated as 1756 and 170 mA/W, respectively.In addition, the specific detectivity calculations, the e×ect of bias, and vigorous bendingtest results are discussed as well. Our work provides the following unique advantages:(i) to the best of our knowledge, the first demonstration of a single SiC nanowire PD ona flexible substrate with great performance, (ii) a very cost-e×ective fabrication methodand readily applicable to any substrate, (iii) exhibiting high sensitivity and responsivityvalues under UV light at 0 V bias. Therefore, our SiCNW-UVPD device presents anopportunity for low-cost, easy to fabricate, self-powered photodetectors for upcomingfuture technologies such as wearable sensors, electronic skins, and the internet ofthings.