A detailed investigation of a-IGZO thin film-based MSM UV photodetector

Amorphous Indium–Gallium–Zinc–Oxide (a-IGZO) thin films were deposited on silicon and glass substrates using a magnetron sputtering system at room temperature. The structural, morphological, optical, and electrical properties of the films were systematically investigated to evaluate their suitability for ultraviolet photodetection. Secondary Ion Mass Spectrometry and Atomic Force Microscopy were employed to characterize the film composition and surface topology, while Hall Effect and Current–Voltage measurements were used to assess the electrical performance. The optical properties were analyzed in the 200–1100 nm spectral range using UV–VIS spectroscopy. A Metal–Semiconductor–Metal (MSM) photodetector was fabricated using a-IGZO film. The average transmittance of the film is 80%, an estimated optical energy gap value is 3.1 eV, and the band tail width is 382 meV. The electrical results for carrier density, mobility, and resistivity were determined to be 4.88 × 1019 cm− 3, 7.83 cm2/V.s, and 1.64 × 10− 2 Ω.cm, respectively. The FoM is calculated as 1.27 × 10− 4 Ω−1. a-IGZO MSM photodetector output parameters at 385 nm ultraviolet illumination, such as responsivity, detectivity, noise equivalent power, photo-to-dark current ratio, and normalized photo-to-dark current ratio at the critical voltage are determined as 12.72 A/W, 1.13 × 1013 Jones, 7.69 × 10− 13 W/Hz1/2, 0.386, and 3.96 × 105 W− 1, respectively. The results demonstrate that the a-IGZO MSM device exhibits behaviors comparable to those in the literature of ultraviolet photodetectors, confirming the potential of a-IGZO as a promising material for advanced optoelectronic applications.