Crystallization and surface segregation in CuIn0.7Ga0.3Se2 thin films on Cu foils grown by pulsed laser deposition

• Published in: Applied surface science 2010-09, Vol.256 (22), p.6819-6823
• Main Authors: Jo, Yeon Hwa, Mohanty, Bhaskar Chandra, Cho, Yong Soo
• Format: Article
• Language: English
• Subjects: ABLATION; CIGS; Composition; defects and impurities; Condensed matter: structure, mechanical and thermal properties; Copper; Cross-disciplinary physics: materials science; rheology; Crystallization; DENSITY; DEPOSITION; Exact sciences and technology; FOIL; Foils; Laser deposition; LASERS; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; PARTICULATES; Physics; Pulsed laser deposition; SEGREGATION; Segregations; Single-crystal and powder diffraction; Solid surfaces and solid-solid interfaces; Structure of solids and liquids; crystallography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); THIN FILMS; X-ray diffraction and scattering
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2010.02.091

This work reports unexpected crystallization and segregation behavior of CuIn0.7Ga0.3Se2 (CIGS) thin films deposited on flexible Cu foils by pulsed laser deposition. A composite-type microstructure containing nanometer-scaled CIGS crystallites embedded in amorphous Cu-rich matrix is observed even at the high temperature of 500A degree C. The findings are attributed to very fast condensation of the ablated species and random nucleation induced from the amorphous matrix. Cu-rich particulates tend to precipitate on the film surface, and their average size, shape, number density and composition exhibit a strong dependence on the substrate temperature up to 500A degree C. The similar crystallization properties of the films on Cu foils and glass substrates are noticeable to the use of Cu foils for flexible solar cells.