Development of solar cells on RST-ribbons

When considering the cost of a photovoltaic module, still a large part consists of silicon wafer material. One solution is the usage of ribbon material, which provides moderate quality material at a low cost due to low kerf losses. Here we present the use of Ribbon on a Sacrificial Template (RST) wafers in a classic solar cell process. The quality of this material is determined by Quasi Steady State Photo Conductance (QSSPC) lifetime measurements indicating a minority carrier diffusion length up to 100¿m. The classic solar cell processing combining various metallization techniques like screenprinting and evaporation leads to energy conversion efficiencies up to 11.5% on 11.44cm² large ribbons. A big boost in efficiency is related to the use of plasma texturing, developed at IMEC, which proofs to be a good technique for texturing poly-crystalline material. The results presented in this paper show that RST material can become a cost competitive ribbon technology for solar cell applications.