Optical characterization of epitaxially lifted-off gallium arsenide thin film on acetate
A gallium arsenide (GaAs) thin film with a thickness of 780nm was epitaxially lifted-off (ELO) and transferred onto an acetate. Characterization using photoluminescence (PL) and Raman spectroscopies were then performed to the sample. The PL data indicates that the ELO GaAs/acetate sample has the same peak as that of the as-grown GaAs thin film. Additionally, there is a degradation of the optical quality of the film as seen by a broadening of its registered PL peak. On the other hand, fluence dependent Raman spectroscopy shows that there occurs a Raman shift at higher laser intensities for the as-grown sample, indicating a strain in the sample. However, further research is needed to confirm the exact cause of this phenomenon. Furthermore, no peak shifts were observed for the ELO GaAs/acetate sample at all laser intensities. We can conclude that the ELO technique is a capable and viable option to fabricate GaAs thin films on plastic.