Simulation-based roadmap for the integration of poly-silicon on oxide contacts into screen-printed crystalline silicon solar cells

article
2021
authors
Kruse, C. N. and Schäfer, S. and Haase, F. and Mertens, V. and Schulte-Huxel, H. and Lim, B. and Min, B. and Dullweber, T. and Peibst, R. and Brendel, R.
journal
Scientific Reports
doi:10.1038/s41598-020-79591-6

abstract

We present a simulation-based study for identifying promising cell structures, which integrate poly-Si on oxide junctions into industrial crystalline silicon solar cells. The simulations use best-case measured input parameters to determine efficiency potentials. We also discuss the main challenges of industrially processing these structures. We find that structures based on p-type wafers in which the phosphorus diffusion is replaced by an n-type poly-Si on oxide junction (POLO) in combination with the conventional screen-printed and fired Al contacts show a high efficiency potential. The efficiency gains in comparsion to the 23.7% efficiency simulated for the PERC reference case are 1.0% for the POLO BJ (back junction) structure and 1.8% for the POLO IBC (interdigitated back contact) structure. The POLO BJ and the POLO IBC cells can be processed with lean process flows, which are built on major steps of the PERC process such as the screen-printed Al contacts and the backslashtextAl_backslashtext2 backslashtextO_backslashtext3 /backslashtextSiN Al2O3/SiNpassivation. Cell concepts with contacts using poly-Si for both polarities (backslashtextPOLO²POLO2-concepts) show an even higher efficiency gain potential of 1.3% for a backslashtextPOLO²POLO2BJ cell and 2.2% for a backslashtextPOLO²POLO2IBC cell in comparison to PERC. For these structures further research on poly-Si structuring and screen-printing on p-type poly-Si is necessary.