On-line monitoring of solar cell module production by ellipsometry technique

THIN SOLID FILMS

卷:571

Article; Proceedings Paper

Fried, M.^1,2 

[1] Inst Tech Phys & Mat Sci, Res Ctr Nat Sci MTA TTK MFA, H-1525 Budapest, Hungary

[2] Univ Pannonia, Fac Informat Technol, Doctoral Sch Mol & Nanotechnol, H-8200 Veszprem, Hungary

关键词: Ellipsometry;    Mapping;    Thin film;    Photovoltaic;    Solar cell;   

DOI  :  10.1016/j.tsf.2014.03.058

来源: Elsevier

【 摘 要 】

Non-destructive analyzing tools are needed at all stages of thin film photovoltaic (PV) development, and on production lines. In thin film PV, layer thicknesses, micro-structure, composition, layer optical properties, and their uniformity (because each elementary cell is connected electrically in series within a big panel) serve as an important starting point in the evaluation of the performance of the cell or module. An important focus is to express the dielectric functions of each component material in terms of a handful of wavelength independent parameters whose variation can cover all process variants of that material. With the resulting database, spectroscopic ellipsometry coupled with multilayer analysis can be developed for on-line point-by-point mapping and on-line line-by-line imaging. This work tries to review the investigations of different types of PV-layers (anti-reflective coating, transparent-conductive oxide (TCO), multi-diode-structure, absorber and window layers) showing the existing dielectric function databases for the thin film components of CdTe, CuInGaSe2, thin Si, and TCO layers. Off-line point-by-point mapping can be effective for characterization of non-uniformities in full scale PV panels in developing labs but it is slow in the on-line mode when only 15 points can be obtained (within 1 min) as a 120 cm long panel moves by the mapping station. In the last years [M. Fried et al., Thin Solid Films 519, 2730 (2011)], instrumentation was developed that provides a line image of spectroscopic ellipsometry (wl = 350-1000 nm) data. Up to now a single 30 point line image can be collected in 10 s over a 15 cm width of PV material. This year we are building a 30 and a 60 cm width expanded beam ellipsometer the speed of which will be increased by 10x. Then 1800 points can be mapped in a 1 min traverse of a 60 * 120 cm PV panel or flexible roll-to-roll substrate. (C) 2014 Elsevier B.V. All rights reserved.

【 授权许可】

Free