Photoresponse of porous silicon for potential optical sensing

¹ Department of Materials Science and Engineering, National Yang Ming Chiao Tung University 300, Hsinchu, Taiwan
² Department of Metallurgical Materials and Materials Engineering, Indian Institute of Technology Jodhpur Jodhpur, Rajasthan-342030, India
³ Centre for Nanoscience and Nanotechnology, Jamia Millia Islamia (Central University) - New Delhi 110025, India
⁴ Department of Chemistry, College of Science, Jazan University - P.O. Box 114, Jazan 45142, Saudi Arabia
⁵ Nanoscience and Technology Program, National Taiwan University - 115, Taipei, Taiwan
⁶ Department of Materials Science and Engineering, National Tsing Hua University - 30013, Hsinchu, Taiwan
⁷ Department of Physics, College of Science, Jazan University - P.O. Box 114, Jazan 45142, Saudi Arabia
⁸ State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University 310027, Hangzhou, PRC

^(a) afzalkhan@zju.edu.cn (corresponding author)

Received: 16 April 2022
Accepted: 29 June 2022

Abstract

In this work, porous silicon (P-Si) structures were fabricated by anodizing n-type monocrystalline Si into an ethanoic-HF solution. Anisotropic electrochemical etching with constant time and current density was carried out to fabricate pores and their average diameter was found to be . Raman spectra exhibited widened peaks for red, blue, and green wavelengths. The widened photoluminescence (PL) spectrum was blue-shifted owing to the quantum confinement effect. The P-Si exhibited an energy gap of 1.80 eV and manifested a direct bandgap. The photoresponse of the fabricated P-Si based device was studied at different laser irradiation wavelengthsin the range of 400–1100 nm. The best photoresponse was observed for 785 nm wavelength and the corresponding sensitivity was determined to be 9.4%. Hence, the P-Si can potentially be used for visible range photodetectors.