Micro-Raman mapping on layers for crystalline silicon thin-film solar cells

• Published in: Journal of crystal growth Vol. 314; no. 1; pp. 53 - 57
• Main Authors: Kunz, T., Hessmann, M.T., Meidel, B., Brabec, C.J.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2011; Elsevier
• Subjects: A1. Micro-Raman; A1. Recrystallization; A3. Chemical vapor deposition processes; Applied sciences; B2. Semiconducting silicon; B3. Solar cells; Boundaries; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Defects and impurities in crystals; microstructure; Energy; Exact sciences and technology; Growth from melts; zone melting and refining; Mapping; Materials science; Methods of crystal growth; physics of crystal growth; Natural energy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Photovoltaic cells; Photovoltaic conversion; Physics; Recrystallization; Residual stress; Silicon; Silicon carbide; Solar cells; Solar cells. Photoelectrochemical cells; Solar energy; Stacking faults and other planar or extended defects; Structure of solids and liquids; crystallography; Thin films; B3. Solar cells; A3. Chemical vapor deposition processes; A1. Micro-Raman; A1. Recrystallization; B2. Semiconducting silicon; Cubic lattices; Barrier layer; High density; Epitaxy; Optical phonon; Crystal defect; Thin film; Grain boundary; Optical properties; Phonon mode; Silicon; Raman spectrometry; Thin film device; Semiconductor materials; Twin boundary; Stacking fault; Epitaxial film; Chemical vapor deposition; Preferred orientation; Allotropy; Solar cell; Silicon carbide; Zone melting; Growth mechanism; Recrystallization; Residual stress; Crystal growth from melts
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2010.12.019

Micro-Raman mappings have been used for characterization of our layers system developed for thin-film silicon solar cells. For the cubic SiC barrier layer a preferential orientation of the grains in 〈1 1 1〉 direction normal to the substrate was revealed. A high density of stacking faults resulted in the splitting of transversal optical (TO)-phonon modes, usually only observed in several non-cubic SiC polytypes. Within the silicon layers, which were obtained by zone melting recrystallization (ZMR) and subsequent epitaxial growth, a high residual stress of about 625 MPa was measured near the boundary towards the SiC layer. Outside of this boundary no residual stress could be detected, in spite of commonly found twin boundaries. Thus the main origin of residual stress in the silicon layers is due to the different expansion coefficients of the respective layers, while grain boundaries have no dominant effect.