3D Photovoltaic Sensors for In-Situ Structural Health Monitoring of Advanced Composites

Abstract

This paper reports on work developing an efficient 3D photosensor using Ti microwires and carbon nanotube yarns (CNYs). The 3D PV sensor construction is the basis of ongoing work towards embedded smart composites with intrinsic triboluminescent/mechanoluminescent (TL/ML) features. Nano-TiO2 coated microwires were used as working electrodes (WE). CNYs were twisted around the coated Ti microwire, which functioned to collect and transmit the photogenerated electrons from the completed WE. Attempts were made to optimize the interface between Ti-microwire and TiO2 microfilm with differing numbers of CNYs. The optimized TiO2 thickness was found to be approximately 20 μm. A silver wire was used as a control experiment to compare with the CNYs operating as the counter electrode (CE). The developed 3D photovoltaic (PV) microsensor displayed a photon-to-current conversion efficiency of 0.49%.