Title
Polycrystalline silicon thin films by high-rate electronbeam evaporation for photovoltaic applications - Influence of substrate texture and temperature
Date Issued
01 December 2011
Access level
open access
Resource Type
conference paper
Author(s)
Helmholtz-Zentrum Berlin für Materialien und Energie
Abstract
Polycrystalline silicon (poly-Si) thin-films have the potential to overcome the limits of today's silicon thin-film solar cell technology because of the chance to grow high-quality material by low-cost deposition techniques. As poly-Si thin-film fabrication is independent of rather slow and costly PECVD processes, it is possible to switch to physical high-rate deposition methods such as electron-beam (e-beam) evaporation exhibiting a strong cost-saving potential. In this contribution, the challenges and opportunities of two different poly-Si solar cell preparation techniques using e-beam evaporated silicon are investigated: Thermal solid phase crystallization (SPC) of initially amorphous silicon layers, and direct growth of poly-Si films at elevated temperatures >500°C. For both approaches, attention is given to the interplay between substrate texture, structure of the grown silicon and the final solar cell performance. Poly-Si thin film solar cells with 7.8% conversion efficiency were prepared on a smooth substrate in cooperation with CSG solar, demonstrating the equality of e-beam evaporation as deposition technique compared to PECVD. However since e-beam evaporation leads to a non-conformal deposition of rough surfaces, the implementation of a textured substrate for light trapping is highly desired but still challenging. A different behavior is observed for poly-Si thin films directly grown at higher temperatures. For the best photovoltaic performance, a certain substrate microstructure is even necessary and can be optimized by the use of glass coated by differently textured ZnO films as substrate. © 2011 Published by Elsevier Ltd.
Start page
61
End page
65
Volume
10
Language
English
OCDE Knowledge area
Ingeniería del Petróleo, (combustibles, aceites), Energía, Combustibles
Recubrimiento, Películas
Subjects
Scopus EID
2-s2.0-84855694195
ISSN of the container
18766102
Conference
Energy Procedia: Advanced Inorganic Materials and Concepts for Photovoltaics - Symposium R at the E-MRS 2011 Spring Meeting
Sponsor(s)
The authors would like to thank J. Hüpkes from Forschungszentrum Jülich, Germany, for providing the ZnO:Al layers and CSG Solar, Australia, for providing the glass substrates and the SiN coatings. A. Schöpke from Helmholtz Zentrum Berlin is gratefully acknowledged for carrying out atomic force microscopy analyses. The work has been partially supported by the European Commission by the FP7 research project PolySiMode (Contract No. 240826). T. Sontheimer acknowledges SCHOTT AG for financial support.
Sources of information:
Directorio de Producción Científica
Scopus