Highly and rapidly stabilized protocrystalline silicon multilayer solar cells

We have developed highly stabilized (p-i-n)-type protocrystalline silicon (pc-Si:H) multilayer solar cells. However, the source of the superior light-induced stability of the pc-Si:H multilayer absorbers compared to conventional amorphous silicon (a-Si:H) absorbers remains unclear. Photoluminescence (PL) and Fourier transform infrared (FTIR) spectroscopy measured at room temperature produce strong evidence that nano-sized silicon grains embedded in regularly arranged highly H-2-diluted sublayers suppress the photocreation of dangling bonds. To achieve a high conversion efficiency, we applied a double-layer p-type amorphous silicon-carbon alloy (p-a-Si1-xCx:H) structure to the pc-Si:H multilayer solar cells. The less pronounced initial short wavelength quantum efficiency variation as a function of bias voltage, and the wide overlap of dark current - voltage (J(D)-V) and short-circuit current - open-circuit voltage (J(sc)-V-oc) characteristics prove that the double p-a-Si,-,C,:H layer structure successfully reduces recombination at the pli interface. Thus, we achieved a highly stabilized efficiency of 9.0 % without any back reflector.