Improved optical and electrical response by glancing angle synthesized Al2O3 nanorod array device

An Aluminum Oxide (Al2O3) nanorod (NR) array-based device has been synthesized upon an Al2O3 thin film (TF) by electron beam (E-beam) evaporation with a glancing angle deposition technique. The complete fabrication has been done inside a vacuum coating unit. The Al2O3 nanostructures have been fabricated on a silicon substrate. Field emission scanning electron microscopy and transmission electron microscopy show a vertically aligned Al2O3 NR array. From the Tauc plot, the optical band energies are estimated as 5 eV and 5.5 eV for the bare Al2O3 TF and Al2O3 NR/Al2O3 TF devices, respectively. Significant improvement has been observed in photosensitivity by 10 fold, detectivity by 4.2 fold, and noise equivalent power (NEP) by 16.5 fold for the Al2O3 NR/Al2O3 TF device compared with the Al2O3 TF. The Al2O3 NR/Al2O3 TF device exhibits a very fast photoswitching response (rise time = 0.15 s and fall time = 0.13 s). Therefore, the Al2O3 NR/Al2O3 TF device proves to be a prominent candidate for next-generation optoelectronic device applications.