In this work, spin-on processes were used to improve front- and rear-side technologies of solar cells to increase efficiencies to >20 %. A limited source diffusion process was developed using phosphoric acid dopant solutions developed in-house. An optimal emitter was obtained to be used in conjunction with screen-printed contacts. This emitter was used to improve the efficiency of conventional full aluminum back surface field solar cells to 19.6 %. A streamlined process was then developed to fabricate high-efficiency dielectric rear passivated cells in a single high temperature step. This process combined the diffusion process described earlier with a spin-on dielectric for rear passivation to achieve solar cell efficiencies of ~20%. Several laser candidates were investigated to improve process reproducibility and throughput. Ultra-violet laser with nanosecond pulse width was identified as the optimal choice. Cell efficiencies of ~20% were reproduced using UV laser for ablation of rear dielectric. This cell design and process were transferred to low-cost low-lifetime commercial grade substrates after identifying the optimal substrate characteristics using modeling.
| Identifer | oai:union.ndltd.org:GATECH/oai:smartech.gatech.edu:1853/44771 |
| Date | 21 May 2012 |
| Creators | Ramanathan, Saptharishi |
| Publisher | Georgia Institute of Technology |
| Source Sets | Georgia Tech Electronic Thesis and Dissertation Archive |
| Detected Language | English |
| Type | Dissertation |
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