Abstract
Aluminium oxide (Al2O3)functions doubly as a high-quality surface passivation material for crystalline silicon and as an aluminium (Al) p-type precursor for laser doping. Thus, p+ doping based on laser ablation of Al2O3 thin-films deposited on a silicon substrate is an attractively simplified process for concurrent local contact definition and aligned surface doping. A number of studies have demonstrated this process, but a careful examination of the influence of laser parameters on the electronic properties of the Al laser doped p+ surface itself, including the influence of post-doping annealing, has yet to be presented. Such information is valuable for establishing process windows and for providing parameters by which the contact geometry can be optimized and the performance of locally Al2O3laser doped solar cells predicted. In this work, we present accurate characterization of the electronic properties of primary importance to solar cell performance: effective surface recombination and contact resistivity. Recombination at the Al2O3laserdoped p+ surface is found to exceed that of equivalently-doped p+ silicon from furnace diffused boron, while contact resistivity to vacuum evaporated Al is up to two orders of magnitude less than screen-printed, fired Al. Based on this characterization, computersimulations demonstrate that with optimized rear contact geometries, an industrially relevant PERC cell can approach 21 % efficiency, and the high-performance UNSW PERL structure can exceed 24 %.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.