Selective Femtosecond Laser Lift-off Process for Scribing in Thin-film Photovoltaics

Laser applications in thin - film photovoltaics

We review laser applications in thin-film photovoltaics (thin-film Si, CdTe, and Cu(In,Ga)Se2 solar cells). Lasers are applied in this growing field to manufacture modules, to monitor Si deposition processes, and to characterize opto-electrical properties of thin films. Unlike traditional panels based on crystalline silicon wafers, the individual cells of a thin-film photovoltaic module can be ...

Process Development for CIGS Based Thin Film Photovoltaics Modules

SELECTIVE UV-LASER PROCESSING FOR LIFT-OFF OF GaN THIN FILMS FROM SAPPHIRE SUBSTRATES

Gallium nitride (GaN) thin films on sapphire substrates were successfully separated and transferred onto Si substrates by pulsed UVlaser processing. A single 600 mJ/cm, 38 ns KrF excimer laser pulse was directed through the transparent substrate to induce a rapid thermal decomposition of the GaN at the GaN/sapphire interface. The decomposition yields metallic Ga and N2 gas that allows separatio...

Development of Flexible Cu(In,Ga)Se2 Thin Film Solar Cell by Lift-Off Process

Thin-film III-V solar cells using epitaxial lift-off

Epitaxial lift-off is used to create thin-film III-V solar cells without sacrificing the GaAs wafer. It is based on selective etching of an AlAs release layer between the wafer and the cell structure using an HF solution. The wafer can be reused for subsequent deposition runs thereby reducing the cost of the cells. The thin-film cell can be transferred to any new carrier, e.g. glass, plastic, s...