Hydrogenation and Gettering Compatible p-Type Contacts for Multicrystalline Silicon Cells, Free of Light, and Elevated Temperature Induced Degradation

Results for a room temperature contacting method applied to the p-type rear surface of monocrystalline and multicrystalline solar cell structures are presented. Monocrystalline silicon devices with the rear contacts prepared using the point contacting by localized dielectric breakdown method are reported with an efficiency of 19.2%. The devices show improved measurements of key performance metrics of rho(c) of 1.6 +/- 0.8 m omega cm(2) and J(0)(c) of 2100 +/- 650 fAcm(-2). This contacting approach is also demonstrated for multicrystalline silicon cells, with no evidence of parasitic breakdown at grain boundary sites. The multicrystalline device implementation highlights a key advantage of this contacting method, namely a relatively free choice of annealing temperature. This flexibility allows process optimization such that the activation of light-and-elevated-temperature-induced degradation is prevented in hydrogenated multicrystalline silicon, while still maximizing the benefits to bulk lifetime.