Enhancing the temporal response of modified porous silicon-based CO gas sensor

In this paper, the role of gold nanoparticles on the temporal response of a porous silicon gas sensor has been studied. The porous layer was prepared by a laser-assisted etching process using 810 nm wavelength and 2 W infrared laser diode as an illumination photonics source. The experimental etching conditions involve 20 mA/ cm2 current density and 10 min etching time. Gold nanoparticles were incorporated into porous silicon structures via the ion reduction process. The characteristics of sensors were studied comprehensively by SEM, XRD, and the electrical properties were investigated for the sensor before and after the gold nanoparticles incorporation process. The obtained results manifested that the decay time of the sensor was reduced by a factor almost greater than (50%) as compared with the bare porous silicon sensor. The results were discussed based on the role of gold nanoparticles that enhanced the thermal conductivity of porous silicon. A higher thermal conductivity of about (130 W/mK) due to the gold nanoparticles was achieved as compared with the bare porous silicon gas sensor.