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.

Tuning Optoelectronic Properties of 4H-SiC QDs Using -H, -OH and -F Surface Functionalisation

“…Previous reports provide some useful insight into the effects of surface passivation of mainly 3C-SiC (ß-SiC) [3][4][5] where the optical gap can be engineered as a function of size and surface composition. The present study is mainly focussed on addressing the issue for arguably the most technologically relevant SiC 4H-polytype [6,7], by terminating the surface atoms of 4H-SiC QDs with various functional groups that are promising in terms of tuning the optical properties and improving the ambient chemical stability.…”

Thermal Stress Response of Silicon Carbide pin Diodes Used as Photovoltaic Devices

“…Given this, there is a clear need, and desire, to develop resilient energy harvesting technologies that can support and power electronics deployed in these resilient environments. Previous work has shown silicon carbide UV photovoltaics to be effective energy harvesters at elevated temperatures [5,6] however they have so far only considered for short term temperature elevation. It has been shown that silicon carbide can survive at 400 °C for extended periods [7] and remain electrical and mechanically operational, however what has not been conducted is a study into the long term resilience of the device metalisation and overall long term temperature effects on devices such as these.…”