Investigation of Ag/BG-Si3N4/n-Si Schottky type photodetector for various BG content

Photodetectors can be used to detect sunlight intensity or light at the specific wavelengths of the electromagnetic spectrum (UV to NIR). In this study, we deposited Si3N4 interfacial layer with various amount of bioactive glass (BG) compositions on the n-type Si to fabricate Ag / BG–Si3N4/n-Si Schottky photodetectors (SPDs) with a reference Ag/n-Si SPD. The characterization of BG-Si3N4 composites were based on Fourier-transform infrared (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The current-voltage ( I-V ) and current-transient ( I-t ) measurements were employed to characterize the fabricated Ag / BG–Si3N4/n-Si SPDs to explore the effects of electrical properties at various light power densities and wavelengths. Electrical parameters such as ideality factor, barrier height, and series resistance were determined using different techniques of thermionic emission, Cheung and Norde methods, and they were examined in detail as a function of light power density. Moreover, to evaluate the photodetector performance, responsivity, detectivity and other relevant parameters were discussed in terms of both light power density and broad spectral range (UV–NIR) for changing content of BG in the interlayers. The results showed high responsivity of 12.61 A/W and specific detectivity of 1.38 × 1011 Jones under sunlight. These findings suggest that Ag / BG–Si3N4/n-Si SPDs are promising optoelectronic devices, especially for broad-spectrum light sensing applications.