NOVEL TCO DEPOSITION TECHNOLOGY FOR IMPROVED PV-CELL PERFORMANCE AT LOWER COST
Drs. E. Ryabova, A. Skumanich, and M. Shkolnikov | PV SEC 25th International Conference Proceedings, September 2010, Valencia, Spain
Highly scalable disruptive thin film deposition technology is developed and validated based on a modified sol-gel method in response to PV-industry quest for the high quality-low cost methods of fabricating PV-cell structures. This "liquid" based approach is envisioned to replace currently used vacuum (PVD and CVD) methods to enable high throughput conveyer type processing of PV-cells with enhanced performance due to the outstanding purity, uniformity and extended interface engineering capability of this method. Solution Derived Nanocomposite (SDN®) technology offers an unmatched potential for TCO electrode materials design and engineering in terms of composition and microstructure without using cost prohibitive solutions. Wide variety of binary and ternary compounds can be formed at the fraction of cost of vacuum methods. Tunability of optical and electrical properties has a wide process window for example for Al-doped ZnO that is particularly useful for the variety of PV-cells’ architectures. The data presented bellow indicates that SDN® provides an enabling technology as a new material for ultra-thin and flexible PV-cell fabrication as well as for the new cell concept implementation.
NOVEL BACK SURFACE FIELD (BSF) STRUCTURE FORMATION BY MODIFIED SOLUTION DERIVED NANOCOMPOSITE (SDN®) METHOD FOR LOW COST NEW CELL CONCEPT IMPLEMENTATION
Drs. E. Ryabova, A. Skumanich, and M. Shkolnikov | IEEE 35th PV SC International Conference Proceedings, June 2010, Honolulu, HI, USA
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.