Progress in the development of high-conversion-efficiency a-Si/μc-Si tandem solar module using μc-Si thin film with high deposition rate on Gen. 5.5 large-area glass substrate
The technology to make high-quality, high-reliability solar modules with a high deposition rate for μc-Si thin-film is a problem for the industrialization of low-cost, high-conversion-efficiency a-Si/μc-Si tandem structure solar modules. Sanyo has solved this problem by developing an original CVD technique called Localized Plasma Confinement CVD and a new evaluation method for μc-Si thin film. A stabilized conversion efficiency of 10.0% was achieved for an a-Si/μc-Si tandem structure solar module, and a deposition rate of 2.4 nm/s for μc-Si thin-film was attained on a Gen. 5.5 full-size glass substrate. To obtain a higher conversion-efficiency a-Si/μc-Si tandem structure solar module, fundamental studies of μc-Si thin-film have been performed, and a stabilized conversion efficiency of 10.5% (Initial solar module conversion efficiency: 12.0%) has been achieved on a large-area glass substrate. Furthermore, in the study of this development, the highest stabilized conversion efficiency of 12.0% (Initial conversion-efficiency: 13.5%) was attained. Module reliability tests confirmed by IEC 61646 Ed. 2 revealed that the performance of the module is adapted. These high-performance a-Si/μc-Si tandem structure solar modules were prepared by using the knowledge of our thin-film and module technologies.
Correlation between Microstructure and Photovoltaic Performance of Polycrystalline Silicon Thin Film Solar Cells
Intrinsic polycrystalline silicon (poly-Si) thin films have been prepared by plasma enhanced chemical vapor deposition at a very high excitation frequency (100 MHz) for the development of p–i–n junction solar cells. The correlation between poly-Si microstructure and photovoltaic performance of poly-Si solar cells has been investigated as a function of deposition parameters such as deposition pressure, SiH4 flow rate and SiH4 concentration. It is found that the poly-Si microstructure including crystalline volume fraction, Xc, and crystallographic orientation is closely related to the atomic hydrogen flux during film growth, which is evidenced by plasma diagnostics in the in situ measurement of optical emission spectroscopy. Basically, with an increase in Xc, open circuit voltage tends to decrease, while poly-Si with Xc > 50% and (220) preferential orientation is essential for high short circuit current. Based on these results, the role of poly-Si microstructure in the photovoltaic performance of poly-Si solar cells is discussed.
Negotiating the cultural and economic outcomes of sport heritage attractions: the case of the National Baseball Hall of Fame
ABSTRACT Contemporary museums must balance their roles as commercial entities and repositories of various, and often dissonant, heritages and histories. Sports museums in particular often have clear commercial and nostalgic aims, particularly through tourist visitation, though the extent to which they represent more challenging narratives remains unclear. This paper examines how one of the most famous sports museums in the world, the National Baseball Hall of Fame (NBHF) in Cooperstown, New York, balances its dual role as tourist attraction and repository of baseball's sometimes checkered past. It was found that different sections of the museum provide greater or lesser degrees of engagement with more controversial issues, although the commercial outputs and appeal of the museum remains clear throughout. Utlimately, the NBHF demonstrates that balancing veneration and critique in collections can be commercially prosperous, and can provide a template for other sport and popular culture museums who may be wary of incorporating more challenging narratives in their exhibits. Furthermore, the symbiotic relationship between the Hall of Fame and the village of Cooperstown, particularly in creating and maintaining cultural and economic outputs, requires further exploration.