United Solar Ovonic has been awarded a $9.1 million contract by the US Air Force Research Laboratory to develop solar cells with a specific power level of 2kW/kg for satellites, airships and unmanned air vehicles. The 2kW/kg target could be achieved with 100µ-thick amorphous silicon cells fixed to a 25µ-deep polymer substrate. The cells have an amorphous silicon structure with three layers, known as a triple junction. The top layer captures light in the blue spectrum, the middle layer in the green wavelength and the bottom layer red light.

United Solar Ovonic has been working with AFRL space vehicles directorate's advanced space power generation group for four years on the technology. Chief operating officer Subhendu Guha says that, as well as collaborating with AFRL, "we are working with several aerospace companies on UAV, airship and satellite applications".

The latest 18-month contract is an extension of earlier work. Solar cells with a specific power approaching 1kW/kg have already been demonstrated. The AFRL's Tacsat 2 satellite, launched in December last year, is using solar cells on a 25µ steel foil with a similar specific power.

Source: Flight International