%0 Journal Article
%T Detailed Study of the Correlation between Cross-Linking of Thick SU-8 and UV-NIR Optical Transmission/Photoluminescence Spectroscopy.
%A Alharbi A
%A Almutairi D
%A Hussain H
%A Alfihed S
%J Polymers (Basel)
%V 15
%N 19
%D 2023 Sep 23
%M 37835915
%F 4.967
%R 10.3390/polym15193866
%X SU-8 polymers are promising materials for various applications due to their low cost, excellent thermal stability, and outstanding mechanical properties. Cross-linking of SU-8 is a crucial process that determines the properties of the materials. This study investigates the effect of cross-linking of free-standing SU-8 films on optical transmission and PL emission under various curing conditions. Our findings show that an increase in the cross-linking density reduces optical transmission and causes a red shift of the PL emission band peaks. By directly measuring the optical response of the isolated SU-8, we remove any uncertainty due to the substrate's presence. Moreover, we show that optical transmission and PL spectroscopy are two non-distractive techniques that can be employed to monitor the curing of the SU-8. This finding enhances our understanding of the cross-linking process in SU-8 and paves the way to further enhance the properties of the SU-8 polymer for various electronics and optoelectronics applications.