Silicon Nanowire-Based Metal-Semiconductor–Metal (MSM) Device for Photodetection Applications

This study investigates the fabrication of silicon nanowires (SiNWs) through the n-type silicon using the metal-assisted chemical etching (MACE) technique for photodetection applications. The synthesized SiNWs underwent comprehensive material characterization using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), atomic force microscopy (AFM), and Fourier-transform infrared spectroscopy (FTIR). These analyses confirmed the uniformity and purity of the nanowires. Electrical measurements, specifically I–V characteristics, were conducted to evaluate the conductivity, carrier mobility, and electronic properties of the SiNWs. A metal-semiconductor–metal (MSM) device has been fabricated incorporating these SiNWs and shows the high current density with 1–<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5~\mu $ </tex-math></inline-formula>A current at ±5 V. Moreover, the device shows a good photoresponse with enhanced photocurrent 7.5 and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$6.1~\mu $ </tex-math></inline-formula>A at +5 and −5 V, respectively, under 650 W/m2 optical illumination. Furthermore, the MSM device demonstrates a very prompt risetime (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\unicode {0x01AE}}_{\text {Rise}}$ </tex-math></inline-formula>) of 1.25 s and a falltime (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\unicode {0x01AE}}_{\text {Fall}}$ </tex-math></inline-formula>) of 2.7 s under 650 W/m2 illuminations. The results underscore the potential of MACE-grown SiNWs in developing high-performance photodetectors, emphasizing their suitability for integration into advanced optoelectronic devices. These findings highlight the promising capabilities of SiNWs in photodetection, paving the way for their application in next-generation optoelectronic technologies.