Development of n-μc-SiOx:H as cost effective back reflector and its application to thin film amorphous silicon solar cells

• Published in: Solar energy Vol. 97; pp. 591 - 595
• Main Authors: Banerjee, C., Srikanth, T., Basavaraju, U., Tomy, R.M., Sreenivasan, M.G., Mohanchandran, K., Mukhopadhyay, S., Barua, A.K.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-11-2013; Elsevier
• Subjects: Amorphous silicon; Applied sciences; Back reflector layer; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Energy; Exact sciences and technology; Natural energy; PECVD; Photoelectric conversion; Photovoltaic conversion; Solar cells; Solar cells. Photoelectrochemical cells; Solar energy; Thin film; Solar cells; Amorphous silicon; Back reflector layer; PECVD; Thin film; Performance evaluation; Amorphous material; Microcrystalline material; Profitability; Refraction index; Reflector; Oxygen content; Thin film cell; Zinc oxide; Silicon; Capacitive coupling; Electrical characteristic; Silicon solar cells; Aluminium base alloys; Optoelectronic properties; Electrical properties; Doped materials; Aluminium addition; Radiofrequency; Chemical vapor deposition; Phosphorus addition; Solar cell; Single junction solar cell; Silicon oxides; Comparative study
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2013.09.021

•Development of n-μc-SiOx:H back reflector for a-Si/μc-Si solar cells application.•Cost effective replacement of ZnO:Al back reflectors by n-μc-SiOx:H.•In-situ PECVD process for reduced material & equipment cost.
Development of doped silicon oxide based microcrystalline material as a potential candidate for cost-effective and reliable back reflector layer (BRL) for single junction solar cells is discussed in this article. Phosphorus doped μc-SiOx:H layers with a refractive index ∼2 and with suitable electrical properties were fabricated by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) technique, using the conventional capacitively coupled reactors. Optoelectronic properties of these layers were controlled by varying the oxygen content within the film. The performance of these layers as BRL have been investigated by incorporating them in a single junction amorphous silicon solar cell and compared with the conventional ZnO:Al based reflector layer. Single junction thin film a-Si solar cells with efficiency ∼9.12% have been successfully demonstrated by using doped SiO:H based material as a back reflector. It is found that the oxide based back reflector shows analogous performance to that of conventional ZnO:Al BRL layer. The main advantage with this technology is that, it can avoid the ex-situ deposition of ZnO:Al, by using doped μc-SiO:H based material grown in the same reactor and with the same process gases as used for thin-film silicon solar cells.