Effect of pre-cleaning treatment and contact wetting angle in the interface between P-doped Si surfaces and selective solar cell electrodes

Prior to electroless plating of the solar cell electrode, the sample was cleaned with a mixture of a sulfuric acid and peroxide solution and a H2NCH2CH2CH2Si(OC2H5) solution. We measured the de-wetting and contact angles of the solar cell thin film electrode. After SPM and APTES treatments, an excellent hydrophilic contact angle was observed. Our results show that it is more effective to remove oxidizer with SiO2 than HF mixed solutions. When comparing the efficiency, pre-treatment with a NH4F:HF mixed solution was more efficient than pre-treatment with a diluted HF solution. After NH4F:HF mixed solution cleaning, when the electrode was formed, the contact resistance that most directly affected the cleaning effect was 0.8194 ohm/sq, which had three times more improvement effect. It is expected that if an optimum cleaning time and process conditions for each cleaning chemical is developed, more improved contact resistance will be secured when each cleaning chemical is applied.