  Scintillation light from liquid noble gas in a neutrino or dark matter
experiment lies typically within the vacuum ultraviolet (VUV) region and might
be strongly absorbed by surrounding materials such as light guides or
photomultiplier. Tetraphenyl butadiene (TPB) is a fluorescent material and acts
as a wavelength shifter (WLS) which can turn the UV light to the visible light
around a peak wavelength of 425 nm, enabling the light signals to be detected
easily for physics study. Compared with a traditional TPB coating method using
vapor deposition, we propose an alternative technique with a spin coating
procedure in order to facilitate the development of neutrino and dark matter
detectors. This article introduces how to fabricate the TPB film on acrylics
using the spin coating method, reports measurement of sample film thickness and
roughness, shows the reemission spectrum, and quantifies the wavelength
shifting efficiency (WLSE).
