Effect of thermal oxidation process on emitter profiling and solar cell performance

摘要

The control of phosphorus surface concentration is a very important due to that have a strongly effect on solar cell efficiency. Two kinds of phosphorus profiles were simulated Using TSUPREM-4 simulating program, the first emitter profile is obtained with the only pre-deposition process for various diffusion temperature and the second emitter profile by adding a drive-in after introducing thermal dry oxidation step after diffusion process for various diffusion temperature. The first emitters show maximum efficiencies using PC1D simulation program about (η ≈ 16-19%) with emitter surface concentration Ns = (0.8-3) ×1020cm-3 and junction depth (0.35-0.6)μm. For second emitters the surface concentration is reduced with the same diffusion parameters and show improvement of the maximum efficiencies (η ≈ 20-21%) with surface doping concentration Ns = (0.6-2) ×1019 (cm-3) and junction depth (1.3-2.3)μm. The silicon oxide layer thicknesses become thicker for highly surface doped emitters. Silicon solar cell performance and parameters are improved after the thermal dry oxidation process and become more efficient.