N-type silicon solar cells featuring an electron-selective TiO2 contact

In this work, the implementation of an electron-selective TiO₂ contact into n-type silicon solar cells is presented for the first time. The surface passivation performance of atomic layer deposition (ALD) ultrathin TiO₂ on n-type silicon is investigated. Ultrathin TiO₂ film is shown to afford good passivation to non-diffused n-type silicon surface. N-type silicon solar cell with an efficiency of up to 19.8% has been achieved with the implementation of an electron-selective TiO₂ contact at the rear. The cell efficiency is demonstrated to be mainly limited by the degraded passivation quality of TiO₂ film during contact formation annealing at a high temperature. The results show the potential to fabricate high efficiency silicon solar cells with a simple implementation of electron-selective TiO₂ contact.