Dr. Radovan Kopecek obtained his Diploma in Physics at the University of Stuttgart in 1998. In addition, he studied at Portland State University (Oregon, USA), where he obtained a Master of Science in 1995. In 2002 he finalizes his PhD dissertation in Konstanz.
Until the end of 2006 he was a group leader at University of Konstanz. One of the founders of ISC Konstanz, Dr. Kopecek has been working at the institute as a full time manager and researcher since 2007 and is currently the head of the Advanced Solar Cells department. Dr. Kopecek is since 2016 in the board of directors of EUREC.
Title and Abstract of the Speech:
PERC and future technologies after
ISC Konstanz, Germany
Since 2016, when LONGi began introducing their low-cost Cz-Si wafers to the PV market, mc-Si and homogeneous Al-BSF technologies have been rapidly losing market share. Back then, there was stiff competition between passivated emitter and rear cell (pPERC) and passivated emitter, rear totally diffused (nPERT) technologies, but PERC later prevailed – mostly because of the cheaper price of p-type wafers and associated processing sequences and materials (e.g. Ag and Al pastes). An additional advantage of PERC was the fact that the process sequence was closer to that for p-type standard cells, which facilitated a gradual adaptation of existing production lines.
PERC technology subsequently became, much more quickly than anyone expected, the leading solar cell technology, with the highest production capacity and the lowest cost of ownership (COO). Towards the end of 2019, mono PERC production capacity reached about 100GWp, which corresponds to a total annual solar cell production of more than 120GW, equating to a 75% market share. Standard PERC cell efficiencies, however, are expected to reach their limits soon; scientists in the PV community estimate that this will happen at an average production efficiency value of 22.5–23%. To achieve even higher efficiencies with PERC-like solar cells, new technologies will need to be implemented.
This raises the question of which cell concepts will replace PERC as the leading solar cell technology of the future. Or, more specifically: how can the voltage of low-cost industrial solar cells be increased towards 700mV and beyond in order to obtain efficiencies well above 23%? And how can this be achieved at acceptable costs, i.e. without the addition of too many and too costly new process steps?
The presentation will summarize the state of the art PERC technology and discuss what technologies most likely will follow in 3-5 years and 10-15 years. We believe that in the coming 1-3 years PERC will still improve its efficiency slightly naturally reaching 23%+ (better pastes, better material) and low cost n-type technologies (nPERT, IBC) will be implemented as well, reaching Vocs´ of around 700mV and more using advanced screen printing. Within 3-5 years so called passivated contact technology will be ready for market implementation and after 10-15 years even c-Si based tandem solar cells will enter the market.