Research on Crystalline-Silicon Solar Cells with Silicon-Germanium Films

• Main Authors: Pai-Yu Chang, 張百裕
• Other Authors: Jian-Yang Lin
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/hq7kfj

博士 === 國立雲林科技大學 === 工程科技研究所博士班 === 101 === The main purpose of this work is to investigate the process development of poly-SiGe films by aluminum-induced crystallization (AIC) and to form the hetero-structured single-crystalline Si/poly-SiGe solar cells. The device simulation of the hetero-structured sc-Si/poly-SiGe solar cells was done with the T-CAD tool. After the process development of the hetero-structured sc-Si/poly-SiGe solar cells, the photovoltaic (PV) characterization of the hetero-structured sc-Si/poly-SiGe solar cells was carried out under AM1.5G solar illumination. Experimentally, the Al and Ge films were evaporated onto the sc-Si substrate to form an a-Ge/Al/sc-Si structure that was annealed at 450°C–550°C for 0–3 h. The x-ray diffraction patterns confirmed that the initial transition from an amorphous to a polycrystalline structure occurs after 20 min of aluminum-induced crystallization (AIC) annealing process at 450°C. The Micro-Raman spectral analysis showed that the AIC process yields a better poly-SiGe film when the film is annealed at 450°C for 40 min. The poly-SiGe films on sc-Si wafer has higher absorption in the long wavelength range than sc-Si wafer; especially, the poly-SiGe film with smaller energy gap has broader absorption range to increase the efficiency of sc-Si based solar cells. In this work, poly-SiGe film has been used to increase the long-wavelength absorption characteristic of the Si solar cells. The poly-SiGe film can achieve a Δη = 14.661% that η(sc-Si/poly-SiGe) = 14.171%. The sc-Si/poly-SiGe structure can improve the PV performance of the Si-based solar cells.