Molybdenum is commonly used as the electrical back contact for Cu(In,Ga)(Se,S)₂ thin-film solar cells. In order to create a monolithically interconnected device, scribing of the molybdenum layer is required. This scribe, known as the P1 scribe, is commonly carried out through laser processing. Optimization of this laser scribing has been carried out using a 532nm pulsed Nd:YAG laser. It was found that two specific regimes of processing resulted in defect free scribes. These regimes are low fluency and high pulse overlap, and high fluency and low pulse overlap. Film properties, including the microstructure, surface oxidation, and internal stress, were studied to understand their effect on the laser ablation process. It was observed that a thin layer of oxidation resulted in significant heat affected zone during the laser ablation process. A discussion of the optimal film properties and laser processing parameters is presented.

Date Published: 8 October 2014
PDF: 6 pages
Proc. SPIE 9180, Laser Processing and Fabrication for Solar, Displays, and Optoelectronic Devices III, 91800K (8 October 2014); doi: 10.1117/12.2062461

Published in SPIE Proceedings Vol. 9180:
Laser Processing and Fabrication for Solar, Displays, and Optoelectronic Devices III
Edward W. Reutzel, Editor(s)