화학공학소재연구정보센터
Langmuir, Vol.34, No.41, 12234-12243, 2018
VUV Photodeposition of Thiol-Terminated Films: A Wavelength-Dependent Study
Photoinitiated chemical vapor deposition (PICVD) has become attractive for selective and specific surface functionalization, because it relies on a single energy source, the photons, to carry out (photo-) chemistry. In the present wavelength (lambda)-dependent study, thiol (SH)-terminated thin film deposits have been prepared from gas mixtures of acetylene (C2H2) and hydrogen sulfide (H2S) via PICVD using four different vacuum-ultraviolet (VUV) sources, namely, KrL (lambda(peak) = 123.6 nm), XeL (lambda(peak) = 147.0 nm), XeE (lambda(peak) = 172.0 nm), and Hg (lambda = 184.9 nm) lamps. Different lambda influence the deposition kinetics and film composition, reflecting that photolytic reactions are governed by the gases' absorption coefficients, k(lambda). Thiol concentrations, [SH], up to similar to 7.7%, were obtained with the XeL source, the highest reported in the literature so far. Furthermore, all films showed islandlike surface morphology, regardless of lambda.