Allen, ThomasBullock, JamesZheng, PeiVaughan, BenBarr, MatthewWan, YimaoSamundsett, ChristianWalter, DanielJavey, AliCuevas, Andres2021-05-191062-7995http://hdl.handle.net/1885/233264Direct metallization of lightly doped n-type crystalline silicon (c-Si) is known to routinely produce non-Ohmic (rectifying) contact behaviour. This has inhibited the development of n-type c-Si solar cells with partial rear contacts, an increasingly popular cell design for high performance p-type c-Si solar cells. In this contribution we demonstrate that low resistance Ohmic contact to n-type c-Si wafers can be achieved by incorporating a thin layer of the low work function metal calcium (ϕ ~2.9 eV) between the silicon surface and an overlying aluminium capping layer. Using this approach, contact resistivities of ρc ~2mΩcm2 can be realised on undiffused n-type silicon, thus enabling partial rear contacts cell designs on n-type silicon without the need for a phosphorus diffusion. Integrating the Ca/Al stack into a partial rear contact solar cell architecture fabricated on a lightly doped (ND = 4.5 × 1014 cm-3 ) n-type wafer resulted in a device efficiency of η = 17.6% where the Ca/Al contact comprised only ~1.26% of the rear surface. We demonstrate an improvement in this cell structure to an efficiency of η = 20.3% by simply increasing the wafer doping by an order of magnitude to ND = 5.4 × 1015 cm-3This work has been supported by the Australian government through the Australian Renewable Energy Agency (ARENA). The work at the University of California, Berkeley was supported by the Bay Area Photovoltaic Consortium (BAPVC).application/pdfen-AUCopyright © 2016 John Wiley & Sons, Ltdpartial rear contactsdopant-free contactscalciumwork functionbarrier heightcontact resistance201710.1002/pip.28382020-11-23