STRUCTURAL, ELECTRICAL AND OPTICAL PROPERTIES OF TiO₂THIN FILM DEPOSITED ON THE NANO POROUS SILICON TEMPLATE

Abstract

The porous silicon (PSi), which is produced by the electrochemical etching, has been used as a substrate for the growth of the titanium oxide (TiO2) thin films. By using the EBPVD method, TiO2 thin films have been deposited on the surface of the PSi substrate. TiO2/PSi layers were annealed at the temperature of 400[Formula: see text]C, 500[Formula: see text]C and 600[Formula: see text]C for different tests. The morphology and structures of layers were investigated by the scanning electron microscopy (SEM) and X-ray diffraction (XRD). The current–voltage characteristic curves of samples and the ideality factor of heterojunction were studied. The results showed that the electrical properties of the samples change with increase in the annealing temperature. The optical properties of the prepared samples were investigated by using UV–Vis and photoluminescence (PL) spectroscopy. Green light emission of the PSi combined with the blue light and violet–blue emission obtained from the TiO2/PSi PL spectra. The results showed that the optical band gap energy of the PSi has increased from 1.86[Formula: see text]eV to 2.93[Formula: see text]eV due to the deposition of TiO2 thin film.

Electrical Properties of Porous Silicon for N2 Gas Sensor

“…Metals, semiconductors and polymers are reported to be partially deposited or to totally fill PSi pores by using the spin coating electrochemical deposition or liquid contact methods [2,5]. Also, because of its very large surface/volume ratio (hundreds of m 2 /cm 3 ), a high reactivity, and its potential compatibility with silicon-based electronics, the (PSi) is one of the most promising materials for the fabrication of gas sensors [6][7][8].…”