Because most of photoelectric systems have a light
source with a visible-light wavelength ranged between 350
and 700 nm, we hoped to get a high-reflectance material
in the visible-light region. PDMS mixtures mixed with various
kinds of nanoscale powder, including silica (SiO2),
titania (TiO2), calcium carbonate (CaCO3), zirconia
(ZrO), zinc oxide (ZnO), and alumina (Al2O3) were respectively
characterized by UV–vis spectrophotometer. Fig. 3a
shows a reflectance curve of PDMS mixture polymers as a
function of incident wavelength ranged between 200 nm
and 1100 nm. Consequently, we found that the reflectance
of TiO2/ PDMS, which achieved 98%, was the most suitable
candidate in these PDMS mixtures. The TiO2/ PDMS
mixtures could reflect most of visible light and its reflectance
value was better than the value of traditional aluminum
coatings (90%) using as reflective films. Hence, the
PDMS/TiO2 mixtures could substitute for metal coatings
to reflect visible light.