Crosstalk analysis, its effects and reduction techniques among photovoltaic devices used as transparent optical sensors for a wearable line-of-sight detection system

Our group has developed a wearable eye-tracking system that comprises transparent optical sensors on eyeglasses to detect the reflection from the eye and thus, the position of the eye, where photovoltaic cells are used as the sensors. In this paper, crosstalk, or electric interference, among the photovoltaic cells is discussed. The crosstalk makes the neighboring sensors dependent on each other, which leads to large errors in eye-tracking. We experimentally investigated the source of crosstalk by testing different designs of photovoltaic cells and their interconnection. It was revealed that sharing of the electrolyte by the photovoltaic devices was dominant. In addition, overlapping circuits were found to contribute to the crosstalk. We revised the design of the sensors and successfully reduced the crosstalk and improved the accuracy.