| Abstract |
Today, using state-of-the-art technology for manufacturing silicon solar cells, efficiencies of 14.0-16.5 \% on multicrystalline and 16.0-18.0 \% on monocrystalline Si substrates are achieved in production lines. Commonly, these solar cells have a boron-doped p-type base and feature a screen-printed Ag front contact grid on a heavily phosphorus-diffused n+ emitter and a full-area Al rear contact. In this contribution, we discuss the impact of recently developed new processing steps for a further improvement of the cell performance, in particular (i) two layer metallisation - seed and growth, (ii) contacting of blue-sensitive emitters and (iii) rear surface passivation with point contacts. Cell efficiencies above 20 \% are demonstrated after successful implementation of these industrially feasible fabrication steps. Furthermore, a short review is given about new innovative high-efficiency cell concepts including (i) metal wrap through (MWT), (ii) emitter wrap through (EWT) and (iii) back junction back contact (BJBC) silicon solar cells, pointing out the advantages and challenges of these cell structures. Due to the fact that today high-efficiency solar cells are mainly produced on n-type mono Si wafers, we pay special attention to n-type solar cells, comparing boron-doped emitter, aluminium-doped emitter and a-Si:H-c-Si hetero solar cells with each other. |
