Effects of Different Tunnel Layers on the Performance and Light Stability of Electron-Selective TiO2 Contacts

We have investigated effects of different tunnel oxide layers on the performance and light stability of tunnel oxide/TiO 2 stack electron-selective contacts on n-type Si. From XPS analysis, we found that chemical properties of a SiO x interlayer at an interface between a tunnel oxide/TiO 2 stack electron-selective contact and an n-type Si significantly depend on stack materials and fabrication processes of tunnel oxide layers. We also found that although chemical SiO 2 and thermal atomic layer deposited AlOx tunnel layers show higher passivation performance, plasma-enhanced atomic layer deposited AlO x tunnel layers demonstrate light-enhanced τ eff with an ITO capping layer as well as the highest light stability without an ITO capping layer.