Enhancing Detectivity of Indium-Oxide-Based Photodetectors via Vertical Nanostructuring Through Glancing Angle Deposition

• Published in: Journal of electronic materials 2021-06, Vol.50 (6), p.3722-3730
• Main Authors: Nath, Amitabha, Mahajan, Bikram Kishore, Singh, Laishram Robindro, Vishwas, Shubhajit, Nanda, Rajib Kumar, Sarkar, Mitra Barun
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Depletion; Deposition; Electronics and Microelectronics; High resolution; High resolution electron microscopy; Indium; Indium oxides; Instrumentation; Materials Science; Optical and Electronic Materials; Original Research Article; Photosensitivity; Silicon substrates; Solid State Physics; Thin films; Transmission electron microscopy
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-021-08889-6

In 2 O 3 vertical nanostructures (VNS) are fabricated using a glancing angle deposition (GLAD) technique upon an In 2 O 3 thin film (TF) on a n-type silicon (n-Si) substrate. Analysis using high-resolution transmission electron microscopy (HRTEM) and high-resolution x-ray diffraction (HRXRD) revealed that the In 2 O 3 VNS are amorphous in nature. An average ~4.5-fold enhancement in absorption was observed and a microscopic origin was proposed for observed bandgap changes for the n-Si/In 2 O 3 TF/GLAD In 2 O 3 VNS and bare n-Si/In 2 O 3 TF samples in the visible region due to surface-related trap states or oxygen vacancies. The improvement in photodetection was attributed to the presence of a large number of surface-related trap states at the edge of metal contacts. The fabricated VNS detector possesses enhanced photosensitivity (~1.7-fold) due to an efficient photogating effect in the depletion region. A maximum detectivity of ~12.8 × 10 7 Jones was observed for the n-Si/In 2 O 3 TF/GLAD In 2 O 3 VNS device, which possesses ~15.6-fold enhanced detectivity as compared to the bare n-Si/In 2 O 3 TF device. Graphic Abstract