Amorphous silicon oxide and its application to metal/n-i-p/ITO type a-Si solar cells

P-type and n-type amorphous silicon oxide (a-SiO) films with a microcrystalline Si phase were deposited by plasma CVD using a gas mixture of SiH4-CO2H2-B2H6 and SiH4-CO2-H2-PH3, respectively. These films had lower absorption coefficients than conventional a-SiO due to larger oxygen contents and microcrystalline phase, but their conductivities were still high since they contained some microcrystalline Si phase. Furthermore, it was found that it is easier to make microcrystalline a-SiO than a-SiC films at low substrate temperature. By applying these films to the p-layer of metal/nip/ITO type cells, higher performance was obtained, compared to the cells with conventional microcrystalline Si p-layer deposited at lower temperature and conventional a-SiO p-layer. From these results, we consider that these novel a-SiO films with microcrystalline Si phase are a promising material for the window layer of a-Si solar cells.