301. Performance potential of low-defect density silicon thin-film solar cells obtained by electron beam evaporation and laser crystallisation
- Author
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Kyung Hun Kim, U. Schubert, D. Ong, Renate Egan, Jonathon Dore, Rhett Evans, B. Eggleston, Sergey Varlamov, Oliver Kunz, Martin A. Green, and Jialiang Huang
- Subjects
Materials science ,Silicon ,Renewable Energy, Sustainability and the Environment ,business.industry ,lcsh:TJ807-830 ,Energy conversion efficiency ,lcsh:Renewable energy sources ,chemistry.chemical_element ,Dielectric ,Condensed Matter Physics ,Laser ,Electron beam physical vapor deposition ,Electronic, Optical and Magnetic Materials ,law.invention ,Optics ,chemistry ,law ,Optoelectronics ,Grain boundary ,Quantum efficiency ,Electrical and Electronic Engineering ,business ,Common emitter - Abstract
A few microns thick silicon films on glass coated with a dielectric intermediate layer can be crystallised by a single pass of a line-focused diode laser beam. Under favorable process conditions relatively large linear grains with low defect density are formed. Most grain boundaries are defect-free low-energy twin-boundaries. Boron-doped laser crystallised films are processed into solar cells by diffusing an emitter from a phosphorous spin-on-dopant source, measuring up to 539 mV open-circuit voltage prior to metallisation. After applying a point-contact metallisation the best cell achieves 7.8% energy conversion efficiency, open-circuit voltage of 526 mV and short-circuit current of 26 mA/cm2 . The efficiency is significantly limited by a low fill-factor of 56% due to the simplified metallisation approach. The internal quantum efficiency of laser crystallised cells is consistent with low front surface recombination. By improving cell metallisation and enhancing light-trapping the efficiencies of above 13% can be achieved.
- Published
- 2013