Role of double ITO/In₂O₃ layer for high efficiency amorphous/crystalline silicon heterojunction solar cells

The high work function transparent conductive oxide films can be use to modify the front barrier height of amorphous/crystalline silicon heterojunction solar cells. We report the implementation of double ITO/In₂O ₃ films as a front anti-reflection electrode in amorphous/crystalline silicon heterojunction solar cells. The In₂O₃ and ITO films were deposited by in-situ radio frequency (RF) magnetron sputtering system. The thin In₂O₃ films were used to modify the front contact barrier height of amorphous/crystalline silicon heterojunction solar cell due to their high work function while the ITO films were used to improve the conductivity of front transparent conductive oxide layer. We investigated the electrical and optical properties of double ITO/In₂O₃ layer with the variation of film thickness. In order to satisfy the requirement of solar cell applications, the optimum combination of thickness in terms of sheet resistance, resistivity, transmittance, etc. was sought. The double ITO/In₂O₃ layer with the thickness of 80/20 nm were applied as front anti-reflection electrode and the best performance of the device was found to be; V_oc = 670 mV, J_sc = 37.42 mA/cm², FF = 71.16% and η = 17.84%.