Hetero-junction Si based solar cells

The aim of the project is to reduce the cost of solar electricity and therefore to develop a low-temperature technology for highly efficient bifacial and monofacial solar cells (up to ~20 % conversion efficiency) based on crystalline and multicrystalline Si wafers using a combination of the Si solar cell base with nano-size nano-structured a-Si:H (a-SiC:H) and transparent conductive oxide (TCO) layers within the heterojunction (HJ) approach. This will be achieved by addressing the following sub-goals: (i) identify and optimize the preparation steps for Si wafers before the deposition of nano-structured a-Si:H(a-SiC:H) and TCO layers; (ii) identify appropriate properties of nano-structured a-Si:H (a-SiC:H) layers as the thin emitter and the rear bac k side passivation of HJ Si based solar cells; (iii) identify appropriate properties of nano-structured TCO layers as the front and back side electrode for bifacial, and as the front electrode for monofacial HJ Si based cells; (iv) development of a lo w-temperature metallization for HJ solar cells, which will include testing of screen printing, vacuum evaporation and magnetron sputtering techniques. Introduction of the new processes will be demonstrated in an industrial production environment. A new low-temperature low-cost technology for the Si based solar cell processing will be installed in Norway. This will have very large consequences, both for the competitiveness of REC in a rapidly growing, highly competitive, innovation-driven cell manufactur ing industry and for the competitiveness of its feedstock and wafer manufacturing versus other PV technologies, and also for the cost-efficiency of solar electricity in general.