Impact of Ag and Au Metal Contacts on WO3 Nanowires for High Performance Photodetection

Abstract

In this article two different junction devices Ag/WO3 NW/p-Si (p-n junction) and Au/WO3 NW/n-Si (Schottky junction) were contrived under glancing angle deposition (GLAD) induced RF sputtering deposition technique. The FE-SEM (field-emission scanning electron microscopy) and TEM (transmitted electron microscopy) characteristics confirmed the growth of WO3 nanowires (NWs) array of length ~110 nm and diameter of ~45 nm. Moreover, from the I-V characteristics curve the formation of a good Schottky and p-n junction was confirmed with a high rectification ratio (RR) value of 370 and 2208 respectively. The specific detectivity (D*) and noise equivalent power (NEP) of the photodetector (PD) device were found to be <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5.88\times 10^{10}$ </tex-math></inline-formula> Jones, 0.0572 nW and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5.48\times 10^{9}$ </tex-math></inline-formula> Jones, 0.614 nW for Ag/WO3 NWs/p-Si and Au/WO3 NW/n-Si respectively. Furthermore, the device showed fast response with rise and fall time of 6.1 ms, 6.7 ms for Ag/WO3 NW/p-Si and 10 ms, 10.3 ms for Au/WO3 NW/n-Si respectively.