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

作者：Ehsan Md Amimul; Khizar M; Raja M Yasin Akhtar^*; Mei Dongming

来源：Arabian Journal for Science and Engineering, 2014, 39(7): 5347-5353.

DOI：10.1007/s13369-014-1106-7

• Heterostructure
• Quantum efficiency
• Absorber doping
• Recombination velocity
• Spectral response
• Hetero-epitaxial

The electrical transport properties of a-Si/cSi(1-x)Ge(x)/c-Si heterostructure thin-film solar cells are described. A lattice mismatch of similar to 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 (V-OC) 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 similar to 21.19 % was calculated for a-Si/cSi(1-x)Ge(x)/c-Si heterostructure thin-film solar cell.

• 出版日期2014-7