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. The formation of nc-Si:H films was further confirmed by Raman spectroscopy analysis. The UV-Visible spectroscopy analysis showed that the synthesized films had a sharp absorption edge in the visible region and had a direct band gap of ~ 1.94 eV. Finally, nc-Si:H based photo-detector has been prepared at optimized process parameters which showed an excellent response time (1.79 s) and recovery time (1.71 s) along with responsivity (~ 9.8x10-8 A/W), detectivity (~ 5.5x104 Jones) and quantum efficiency (~ 27.37x10-6 %). The obtained results demonstrate a significant step towards nc-Si:H based photo-detector for broad band photo-detection applications.