Fabrication of heterojunction solar cells by using microcrystalline hydrogenated silicon oxide film as an emitter

Wide gap, highly conducting n-type hydrogenated microcrystalline silicon oxide (mu c-SiO : H) films were prepared by very high frequency plasma enhanced chemical vapour deposition at a very low substrate temperature (170 degrees C) as an alternative to amorphous silicon (a-Si : H) for use as an emitter layer of heterojunction solar cells. The optoelectronic properties of n-mu c-SiO : H films prepared for the emitter layer are dark conductivity = 0.51 S cm(-1) at 20 nm thin film, activation energy = 23 meV and E-04 = 2.3 eV. Czochralski-grown 380 mu m thick p-type < 1 0 0 > oriented polished silicon wafers with a resistivity of 1-10 Omega cm were used for the fabrication of heterojunction solar cells. Photovoltaic parameters of the device were found to be V-OC = 620 mV, J(SC) = 32.1mA cm(-2), FF = 0.77, eta = 15.32% (active area efficiency).