Novel Back Surface Field (BSF) structure formation by modified solution derived nanocomposite (SDN) method for low cost new cell concept implementation

A novel technology based on a modified hybrid sol-gel technology is presented with PV cell data showing improved performance capability. This “liquid” based approach is envisioned to replace standard Al-BSF with the novel solution based BSF. This latter method can be readily scaled up to the necessary industrial manufacturing levels for c-Si solar cells of virtually any design. Comparative PV test cells were processed and the data show a simultaneous 30% increase in Voc and Jsc accompanied with red shifted spectral IQE graphs using the solution approach. Improved surface passivation is also observed. These results provide the proof-of-concept data. The key advantage is that with this approach, high-quality films with tunable parameters can be generated using low cost, high throughput, non-vacuum processing. Further, various aspects of the materials generated by this approach will enable higher cell performance by providing flexibility in the range of thin film deposition and for extended interface engineering. The approach assists in the progression of the PV roadmap for advanced cell designs envisioned for improved conversion efficiency, as well as for thinner wafers, both of which will impose significant demands and constraints on processing conditions.