Passivation of boron-doped р+-Si emitters in the (p+nn+)Si solar cell structure with AlOx grown by ultrasonic spray pyrolysis

AlOx/(p+nn+)Cz-Si/IFO and ITO/AlOx/(p+nn+)Cz-Si/IFO solar cell structures have been fabricated from n-type Czochralski (Cz) silicon wafers through boron and phosphorus diffusion for producing the p+-Si emitter and n+-Si layer, respectively. The results demonstrate that the level of p+-Si surface passivation increases with increasing AlOx film thickness and as a result of heat treatment. The optimal sheet resistance of the emitter is ∼65 Ω/□. The pseudo-efficiency of the ITO/AlOx/(p+nn+)Cz-Si/IFO structures was 20.2/18.8% under front/back illumination.