Since experimental techniques to investigate these phenomena in detail would be very difficult and unwieldy to use as an optimisation tool, this thesis advocates an approach based in numerical modelling. In designing new laser-processing approaches and in optimising existing ones, a detailed understanding of the resulting heat transfer, phase change, and other relevant phenomena that occur during the process is arguably valuable. In this respect, laser processing offers advantages in achieving various fabrication steps by providing spatially precise and localised heating on short and controllable timescales, and offering continuous, high throughput, in-line processing. To maintain downward pressure on module prices and to improve efficiencies, continued developments of manufacturing processes are required. Recent developments in solar photovoltaic cell technology have enabled significant cost reductions so that in many markets it is now directly competitive with conventional energy generation. Since the present chapter concerns about the thermal effect on the hydrogen passivation of silicon wafers, the temperature profiles of the steel plate are not presented here. The numerical simulation has been performed using a variety of laser powers, scanning speeds, and initial substrate temperatures to obtain the optimal temperature range along with a similar value of annealing time and cooling rate compared to using the belt furnace and RTP methods for passivating of the crystallographic and B-O defects. The remaining properties, and their corresponding values are summarised in Table A.3, in Appendix A. Since the surface properties for calculating thermal joint conductance were not known during the simulations, the silicon wafer is considered as polished, and the value of RMS surface roughness, σ r, is taken as 0.8 µm, which is reasonable for most of the practical surfaces. A.1, A.2, Table A.1 and A.2, in Appendix A. The thermo-physical and optical properties used in the simulations are summarised in Fig. The rapid cofiring process also prevented junction shunting while maintaining very effective SiNx-induced hydrogen passivation of defects, resulting in an average bulk lifetime exceeding 100 μs.
![solarcell blp solarcell blp](https://oppdthewire.com/wp-content/uploads/2019/06/RENEW_Solar-Panels_homepage.jpg)
![solarcell blp solarcell blp](https://cdn.shopify.com/s/files/1/0219/0154/products/06150m_1024x1024.jpg)
These cells were fabricated using a simple process involving POCl3 diffusion for a high-sheet-resistance emitter, SiNx AR coating and rapid cofiring of Ag grid and Al-doped back-surface field in a conventional belt furnace. This represents the highest-efficiency screen-printed EFG Si cells with single-layer antireflection (AR) coating. emitter produced 16.1% efficient 4 cm2 planar edge-defined film-fed grown (EFG) ribbon Si cells with a low series-resistance (0.8 Ω cm2), high fill factor of ∼0.77, along with very significant bulk lifetime enhancement from 3 to 100 μs. The optimized co-firing cycle developed for a 100 Ω/sq.
![solarcell blp solarcell blp](https://www.clean-energy-ideas.com/wp-content/uploads/2019/06/importance-of-solar-energy.jpg)
High-quality screen-printed contacts were achieved on a high-sheet-resistance emitter (∼100 Ω/sq.) using PV168 Ag paste and rapid co-firing in the belt furnace.