TiO₂ thin films by atmospheric pressure chemical vapor deposition for rear surface passivation of p-PERT solar cells

The aim of this paper was to analyze the passivation of the rear face of silicon solar cells by TiO₂ thin films produced by atmospheric pressure chemical vapor deposition (APCVD). A compact high throughput APCVD system was employed to deposit the TiO₂ films. Silicon solar cells with a n⁺ pp⁺ PERT (passivated emitter rear totally-diffused) structure were produced and characterized. The use of TiO₂ on the rear face resulted in a 0.5 mA/cm² increase in short-circuit current density and a 0.5% absolute improvement in efficiency compared to devices without a passivation layer. Analyzing the internal quantum efficiency of the devices, we concluded that this economically technique provides passivation on the p⁺ surface, doped with boron, similar to that obtained with thermally grown silicon oxide films. (author)