Photocatalytic regeneration of interdigitated capacitor relative humidity sensors fabricated by glancing angle deposition

Glancing angle deposition was used to fabricate TiO2 thin film relative humidity sensors. These sensors have been shown to have an extremely high capacitive response along with sub-second response times. However, the thin film morphology that gives rise to the strong performance also renders the film vulnerable to ageing processes which can degrade sensor performance over a period of days. In this paper, the evolution of sensor response in time was studied. The response of our sensors to ultraviolet irradiation was investigated, and shown to not only reverse the ageing of our sensors, but also increase the overall device response.