Industrially feasible, dopant-free, carrier-selective contacts for high-efficiency silicon solar cells

Dopant-free, carrier-selective contacts (CSCs) on high efficiency silicon solar cells combine ease of deposition with potential optical benefits. Electron-selective titanium dioxide (TiO₂) contacts, one of the most promising dopant-free CSC technologies, have been successfully implemented into silicon solar cells with an efficiency over 21%. Here, we report further progress of TiO₂ contacts for silicon solar cells and present an assessment of their industrial feasibility. With improved TiO₂ contact quality and cell processing, a remarkable efficiency of 22.1% has been achieved using an n-type silicon solar cell featuring a full-area TiO₂ contact. Next, we demonstrate the compatibility of TiO₂ contacts with an industrial contact-firing process, its low performance sensitivity to the wafer resistivity, its applicability to ultrathin substrates as well as its long-term stability. Our findings underscore the great appeal of TiO₂ contacts for industrial implementation with their combination of high efficiency with robust fabrication at low cost.