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. Copyright (c) 2017 John Wiley & Sons, Ltd.