Excellent Response and Recovery Time of Photo-Detectors Based on Nc-Si:H Films Grown by Using Hot Wire Method

Abstract

In present study we have synthesized highly crystalline hydrogenated nanocrystalline silicon (nc-Si:H) thin films by hot wire method. The obtained thin films were characterized by using low angle-XRD, Raman spectroscopy, non-contact atomic force microscopy (NC-AFM) and UV-Visible spectroscopy. The low angle-XRD analysis revealed that the obtained nc-Si:H thin films are polycrystalline and have preferred orientation along (111) direction. Formation of nc-Si:H films are further confirmed by Raman spectroscopy analysis. The UV-Visible spectroscopy analysis showed that the synthesized films have sharp absorption edge in visible region and has direct band gap of 1. 94 eV. Finally, nc-Si:H based photo-detector have been prepared at optimized process parameters which show an excellent response time (1.79 s) and -8 4 -6 recovery time (1.71 s) along with responsivity ( 9.8x10 A/W), detectivity ( 5.5x10 Jones) and quantum efficiency ( 27.37x10 %). The obtained results demonstrate a significant step towards nc-Si:H based photo-detector for broadband photo-detection applications.