Improvement of c-Si surface passivation using dual intrinsic a-Si:H layers for silicon heterojunction solar cells

Crystalline silicon (c-Si) surface should be passivated effectively to reduce the surface recombination losses for silicon heteroj unction solar cells. To prevent the epitaxial growth of a-Si:H films near c-Si surfaces and improve the effective carrier lifetime, dual passivation layers were obtained using inductively coupled plasma chemical vapor deposition process with an intermediate hydrogen dilution for smooth interface layer and high hydrogen dilution for dense cover layer. The effective lifetime and implied open circuit voltage are 148.1 μ s and 663 mV for a dual intrinsic a-Si:H passivated sample which is higher than 137.8 μs and 650 mV of single intrinsic a-Si:H film. Thus, the introduction of dual intrinsic a-Si:H layers is a viable method for the c-Si surface passivation.