Superior photosensing performance by Ag nanoparticles textured Al2O3 thin film based device

摘要

This report discusses about the improvement in photosensing characteristics of a silver (Ag) nanoparticles (NP) textured aluminum oxide (Al2O3) thin film (TF) device by glancing angle deposition (GLAD) technique. This device has been synthesized on n-Si substrates using an electron beam (e-beam) evaporation technique. The samples were then morphologically and crystallographically characterized by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and X-ray diffraction (XRD), respectively. The Ag NP/Al2O3 TF-based device has a two fold improvement in photocurrent compared to the bare Al2O3 TF device owing to the generation of the interfacial trap states. The Ag NP/Al2O3 TF-based device also possessed 3.1 fold enhancement in photosensitivity, improved barrier height (0.80 eV), detectivity (3.7 x 10(7) jones), and noise equivalent power (NEP: 2.17 x 10(-9) W). The Ag NP/Al2O3 TF device has faster photosensing performances (T-r = 0.25 s and T-f = 0.25 s) than the bare Al2O3 TF device (T-r = 0.60 s and T-f = 0.58 s). Therefore, the improved parameters will ensure that the Ag NP/Al2O3 TF device can be used as a fast-switching efficient photosensor.