A New Functional Composite for Photovoltaic and Sensor Applications

Abstract

As a preliminary drive to eventually develop dye‐sensitized solar cell (DSSC)‐powered gas sensors, many oxide‐based systems have been explored to fabricate sensors that can show response at room temperature for any analyte gas. As an outcome of recent work in this endeavor, a composite nanorod of anatase TiO2 with Na0.23TiO2 is found to exhibit both photovoltaic performance and gas sensing at room temperature as demonstrated here. An interesting morphology change along with a phase change from nanoparticle to nanorod is observed during the hydrothermal synthesis of anatase TiO2 nanoparticles with sodium hydroxide under a highly basic condition. In order to understand the effect of the minor phase Na0.23TiO2 on the inherent properties of anatase TiO2, the application of nanorod composite in two unique potential application areas, DSSC and acetone sensings is investigated. The composite material exhibits an enhanced efficiency of 7.85% for a DSSC. Surprisingly, a resistive sensor fabricated with the synthesized composite material exhibits room temperature p‐type sensing behavior toward different concentrations of acetone (10, 5, 3, 2, and 1 ppm) with high selectivity.

Some interesting insights into the acetone sensing characteristics of monoclinic WO3

“…Ltd, Bangalore) inside the sensing chamber (∼25 °C, % RH ∼25%). Similar sensor fabrication details are also reported in our previous publications 32,33 The electrical resistance of the sensor device was measured by varying the operating temperature in the presence of air and acetone by using a digital multimeter (Agilent U1253A) with a constant voltage source (Keithley 228A) and the data was collected with the help of an Agilent GUI Data Logger. The sensitivity percentage ( S %) was calculated as the function where R a and R g represent the electrical resistance of the sensor device in the presence of air and target gas acetone, respectively.…”