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.
High rate growth of microcrystalline silicon at low temperatures
Abstract A high rate growth method of microcrystalline silicon at low temperatures has been developed using plasma enhanced chemical vapor deposition (PECVD). It has been found that energetic positive ion and atomic hydrogen impingement on to a growing surface have important affects and that atomic hydrogen density needs to increase correspondingly to the increasing growth rate, while keeping ion bombardment less. Based on this guide line, a novel control of plasma is demonstrated using a high deposition pressure of 2–4 Torr combined with a depletion condition of source gas (SiH 4 ) at a high RF power (a high-pressure-depletion method) and consequently a growth rate of 1.5 nm/s has been achieved using a conventional radio frequency plasma enhanced chemical vapor deposition at 13.56 MHz. Use of a very high frequency plasma at 60 MHz further increases the growth rate up to 5 nm/s and good crystallinity is maintained up to 3.8 nm/s at 250°C. Atomic hydrogen-mediated growth of crystalline silicon at low temperatures is discussed.
Evaluation of Impact of Yarn Count and Stitch Length on Pilling, Abrasion, Shrinkage and Tightness Factor of 1 ? 1 Rib Cotton Knitted Fabrics
This study investigates the impact of yarn count and stitch length of 100% cotton knitted fabrics. 1 × 1 ribs structured fabrics were used in this research work. The stitch length 2.50 mm, 2.52 mm, 2.60 mm, 2.70 mm, 2.80 mm and 2.96 mm were used of the yarn count of 26Ne, 28Ne and 36Ne. The areal densities of the grey fabrics were in various amounts. The impacts of yarn count and stitch length were measured concerning pilling resistance, abrasion resistance, and shrinkage and tightness factor. The result showed that the fabric pilling grade decreased while number of cycle increased. Abrasion resistance decreased but length wise shrinkage increased despite the fact that the stitch length increased. The results also exposed that the tightness factor of the fabric increased with the increase of the stitch length in both dyeing and washing state and finished state compared to grey state for the yarn count 26Ne and homogeneous result not found for yarn count 28Ne and 36 Ne. Evaluation of Impact of Yarn Count and Stitch Length on Pilling, Abrasion, Shrinkage and Tightness Factor of 1 × 1 Rib Cotton Knitted Fabrics