Good Stability of Protocrystalline Silicon Multilayer Solar Cells Against Light Irradiation Originating from Vertically Regular Distribution of Isolated Nano-Sized Silicon Grains

Photoluminescence and Fourier transform infrared spectra measured at room temperature, and transmission electron microscopy micrographs produce strong evidence that nano-sized silicon grains are embedded in alternately hydrogen-diluted protocrystalline silicon multilayers. We suggest that the vertically regular distribution of isolated nano-sized silicon grains caused by the repeatedly layered structure, as well as the improved structural order in the a-Si:H matrix reduces "slow" metastable defects, resulting in a fast light-induced stabilization with a low degradation