Electricity from concentrated solar IR in solar lighting applications

The sun's energy can be concentrated and it's spectrum divided into visible light and infrared where the visible light can be used for applications such as plant growth or building interior lighting and the IR can be converted to electricity using low bandgap GaSb photovoltaic cells. Physical Sciences Inc. (PSI) has been developing the Solar Lighting System for space based plant growth. As a result, PSI has performed outdoor testing on GaSb cells provided by JX Crystals using concentrated IR solar energy. An efficiency of 15.4% has been measured with a cell output power density of 2.21 W/cm/sup 2/. This efficiency is consistent with indoor flash test data and QE data. The efficiency can be improved to 17.3% using an improved AR coating.