Visible luminescence of nanoporous silicon using alternating current photo-assisted electrochemical etching for potential MSM photodetector

• Published in: Materials Science Forum
• Main Author: Mahmood A.; Hassan Z.; Ahmed N.M.; Shahiri E.; Abd Rahim A.F.; Abdullah M.S.
• Format: Conference paper
• Language: English
• Published: Trans Tech Publications Ltd 2016
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84964871223&doi=10.4028%2fwww.scientific.net%2fMSF.846.274&partnerID=40&md5=fc11bc9c9293ba59f53f4b955b88115c

The formation of nanocrystalline porous silicon (PS) was successfully prepared under a novel alternating current (sine-wave a.c. (50 Hz)) photo-assisted electrochemical (ACPEC) etching condition of an n-type (100) silicon (Si) substrate under the illumination of an incandescent white light. As grown Si and PS through conventional direct current(DC) anodization were also included for comparison. The ACPEC formed porous Silicon (PS) with excellent structural and surface morphological characteristic. According to the field emission scanning electron microscope (FESEM) micrographs, the nanoporous structures exhibited pores with uniform circular structure with estimated sizes, ranging between 20.5 nm and 30.5 nm. The atomic force microscopy (AFM) revealed an increase in the surface roughness induced by porosification. As compared to the asgrown Si, PS by AC method exhibited a substantial visible photoluminescence (PL) intensity enhancement with blue-shift associated with the quantum confinement effect of the nanostructure Si. Thermally treated nickel (Ni) finger contact was deposited on the PS to form MSM photodetector. Ni/PS MSM photodetector showed lower dark and higher photocurrent compared to the as grown Si device. © 2016 Trans Tech Publications, Switzerland.