Silicon Carbide UV Based Photovoltaic for Hostile Environments

Abstract

The development of silicon carbide technologies has allowed for the development of sensors and electronics to measure the changes in a variety of hostile environments. A problem has been identified with reliable and efficient ways to power such sensors in these hostile environments. It is likely to be impractical to run power cables to these sensors and battery power has a finite lifetime. Recent research has demonstrated many energy scavenging techniques but to date none have been developed with a view of operation in hostile environments. To investigate the power density achievable from a SiC based energy scavenging device a SiC pin diode was exposed to both broad spectrum light form a tungsten halogen bulb and a 255 nm UV source. IV and CV measurements were used to determine the structural properties and photovoltaic response of the device, dark saturation current, induced photo current and the fill factor. We present the characteristics and maximum power density of these devices at temperatures between 300 K and 600 K. We demonstrate that the maximum power density achievable decreases with temperature. This is mostly due to the reduction in the built in potential from the pn junction, and the reduction of the generated photocurrent.