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

Abstract

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 N s = (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.