Abstract
In this study, the tensile test have been carried out to commercially available amorphous silicon (a-Si) flexible solar cell and its failure processes have been characterized by acoustic emission (AE) technique. Open circuit voltage (V_<oc>) has been measured simultaneously during the test. V_<oc> starts to decrease at strain of 〜0.9%, and cumulative AE energy of the AE signals with frequency range of 600-800 kHz, which are classified based on wavelet transform analysis, starts to increase at the same time. By observation with scanning electron microscope after the test, it is revealed that mechanical damages due to tensile strain in a-Si solar cell are classified into 4 modes. From V_<oc> measurement during the test, it is considered that different failure modes take place intermittently and have the combined effect on degradation of V_<oc>. In addition, structural factor, such as the location of grid electrode, can affect the failure mode of a-Si solar cell.
