Numerical Analysis of a-Si/c-Si1-x Ge x /c-Si Heterostructures Based on Si and Ge Thin-Film Solar Cells

Autor: Dongming Mei, Md. Amimul Ehsan, Muhammad Khizar, M. Yasin Akhtar Raja
Rok vydání: 2014
Předmět:
Zdroj: Arabian Journal for Science and Engineering. 39:5347-5353
ISSN: 2191-4281
1319-8025
DOI: 10.1007/s13369-014-1106-7
Popis: The electrical transport properties of a-Si/c-Si1- xGex/c-Si heterostructure thin-film solar cells are described. A lattice mismatch of ~4.17 % between Si and Ge is always challenging when considering such material system. Numerical optimization of the layer by layer structure shows that Si absorber and p Si1-xGex strained layers play a critical role to improve the light absorption properties of a-Si/c-Si1-xGex/c-Si heterostructure for their infrared detection applications. For this study, a finite element analysis technique is used to solve the fully coupled two carrier semiconductor transport equations. Obtained results show a substantial enhancement in the conversion efficiency of the newly designed a-Si/c-Si1-xGex/c-Si heterostructure thin-film solar cell. Achieved enhancement in conversion efficiency is attributed due to a noticeable improvement in the open circuit voltage (VOC) and a corresponding increase in the optical path lengths. Comparative study of the Si- and Ge-based thin-film solar cells shows that the conversion efficiency of Si-based heterostructures is better than germanium mainly due to the low thermal and lattice mismatch of Si to the design hetero-epitaxial structure. As much as a conversion efficiency of ~21.19 % was calculated for a-Si/c-Si1-xGex/c-Si heterostructure thin-film solar cell.
Databáze: OpenAIRE
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