Simple silicon solar cells featuring an a-Si:H enhanced rear MIS contact

This paper presents the experimental demonstration of silicon solar cells that incorporate an enhanced MIS passivated contact scheme on a phosphorus diffused surface. By depositing intrinsic a-Si:H on an ultrathin SiOx layer and alloying with an overlying aluminium layer, the interface passivation has been vastly improved over that of conventional MIS contacts, whilst maintaining a low contact resistance. This paper focuses on the optimisation of the Al/a-Si:H alloying process and the influence of the tunnelling SiOx layer thickness. A conversion efficiency of 21.0% has been achieved for n-type cells fabricated with a front boron diffusion and a full area rear MIS passivated phosphorus diffusion. The cells,exhibit a moderate V-oc=666 mV and FF=0.805, whereas J(sc) 39.3 mA/cm(2) is relatively low due to a non-optimal antireflection coating and back surface reflector, and hence will be subject to further improvement. (C) 2015 Elsevier B.V. All rights reserved.