Ultra-thin III-V photovoltaics for space power applications

Lead Research Organisation: University of Cambridge
Department Name: Materials Science & Metallurgy

Abstract

The space industry has expanded rapidly in recent years, driven by increasing demand for communications, navigation, precision timing and satellite imagery. Most satellites are powered by III-V photovoltaics which have high solar energy conversion efficiency and are better able to survive the harsh radiation environments in space than their silicon counterparts.

Ultra-thin (<200 nm) III-V photovoltaics are an emerging device concept, to increase W/kg while also enabling new fully flexible satellite form factors. This technology offers intrinsic radiation tolerance, to enable extended missions in challenging space environments such as polar earth orbits and Jovian exploration. In order to fully absorb incident solar illumination in an ultra-thin semiconductor film, advanced light management approaches are required such as the use of sub-wavelength nanophotonic scattering structures to couple light into laterally propagating modes. In this way, a device which is optically thick but electrically thin can be fabricated.

This project involves the design and hands-on fabrication of semiconductor devices. Techniques will include wafer bonding, chemical etching and lithography (photo-, e-beam and nanoimprint).

Publications

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Description We have designed, fabricated and tested a novel type of solar cell made from ultra-thin layers of III-V semiconductor materials. The ultra-thin geometry gives the devices an intrinsic radiation tolerance and high specific power that makes them ideal for powering spacecraft. We integrated a light-trapping layer into the devices using a process called Displacement Talbot Lithography with collaborators at the University of Bath. The preliminary devices have shown good electrical and optical performance considering their ultra-thin dimensions. We will continue with optimising the design and fabrication processes.
Exploitation Route Future iterations of the device will be exposed to radiation damage to see how resistant they are to the conditions in space. This will hopefully provide further evidence of their application to the space power industry.
Sectors Aerospace, Defence and Marine,Energy