Investigation on Thin Film Solar Array Usin g Lock-In Thermography

After the successful execution of a research project for European Space Agency (ESA) regarding the design, assembly and test of thin film solar array hardware, samples of identical configuration were subject of an investigation with lock-in thermography. The quality of the interconnection of thin film solar cells (TFSCs) and the electrical characteristic of the whole assembly i.e. the identification of shunts were the main points of interests.Three flexible TFSCs were mounted on a flexible substrate and interconnected in series in order to simulate a flexible solar array. A current of 170mA was passed through these cells in a forward direction. The current was periodically switched on and off to provide a pulsed thermal load. This thermal excitation was observed with a micro-bolometer camera. The pictures gained were further processed. Their amplitude and phase information was analysed.