三节非晶硅薄膜太阳能电池.pdf

Three-Terminal Amorphous Silicon Solar Cells Many defects exist within amorphous silicon since it is not crystalline. This provides recombination centers, thus reducing the efficiency of a typical a-Si solar cell. A new structure is presented in this paper: a three-terminal a-Si solar cell. The new back- to-back p-i-n/n-i-p structure increased the average electric field in a solar cell. A typical a-Si p-i-n solar cell was also simulated for comparison using the same thickness and material parameters. The 0.28 µm-thick three-terminal a-Si solar cell achieved an efficiency of 11.4%, while the efficiency of a typical a-Si p-i-n solar cell was 9.0%. Furthermore, an efficiency of 11.7% was achieved by thickness optimization of the three-terminal solar cell. 1. Introduction the final efficiency is limited by the smallest photogenerated current among all subcells [22]. This is because each subcell Amorphous silicon (a-Si) for photovoltaic applications can of a multijunction solar cell must pass through the same be deposited using the techniques of plasma-enhanced current. Therefore, the defects inside the a-Si may reduce chemical vapor deposition (PECVD) [1–3], catalytic CVD the efficiencies of solar cells whether for a single-junction (Cat-CVD) [4, 5], photo-CVD [6, 7], sputtering [8], and so cell or a multijunction cell. The efficiencies are reduced due forth. Since it is usually deposited at a low temperature, low- to the recombination of photogenerated carriers via defects cost or flexible materials like glass, plastic, or stainless steel [23, 24]. In addition, carrier mobility in a-Si is quite low. can be adopted as the substrate. Amorphous Si also has the