Effects of variations in precursor concentration on the growth of rutile TiO2 nanorods on Si substrate with fabricated fast-response metal–semiconductor–metal UV detector

Abstract

This study aimed to investigate the effects of variations in precursor concentration (TiCl3 solution) on the structural, morphological, and optical properties of rutile titanium dioxide (TiO2) nanorods and fabricated metal–semiconductor–metal UV detector depending on the optimal sample. The nanorods were prepared from an aqueous solution of titanium (III) chloride (TiCl3) on p-type, (111)-oriented Si substrates at different concentrations of TiCl3 solutions (2, 3, 4, and 5mM). The experimental results showed that the TiO2 nanorods grown at 4mM concentration exhibited optimal structural properties. A fast-response metal–semiconductor–metal UV detector was fabricated by depositing Pt contacts on the front of the optimal sample via RF reactive magnetron sputtering. Upon exposure to 365nm light (2.3mW/cm2) at 5V bias voltage, the device showed 44.4 sensitivity. In addition, the internal gain was 1.45, and the photoresponse peak was 70mA/W. The response and the recovery times were calculated to be 7.8ms upon illumination to a pulse UV light (365 nm) at 5V bias voltage.