Mechanism of wavelength conversion in polystyrene doped with benzoxanthene: emergence of a complex

Abstract

Fluorescent guest molecules doped in polymers have been used to convert ultraviolet light into visible light for applications ranging from optical fibres to filters for the cultivation of plants. The wavelength conversion process involves the absorption of light at short wavelengths followed by fluorescence emission at a longer wavelength. However, a precise understanding of the light conversion remains unclear. Here we show light responses for a purified polystyrene base substrates doped with fluorescent benzoxanthene in concentrations varied over four orders of magnitude. The shape of the excitation spectrum for fluorescence emission changes significantly with the concentration of the benzoxanthene, indicating formation of a base substrate/fluorescent molecule complex. Furthermore, the wavelength conversion light yield increases in three stages depending on the nature of the complex. These findings identify a mechanism that will have many applications in wavelength conversion materials.

Optical characteristics of pure poly (vinyltoluene) for scintillation applications

“…In this way, coloration and impurities, caused by thermal degradation or oxygen contamination, were reduced in the PVT. Polymerisation was 98.0%, with an average molecular weight of 550,000 and a density of 1.02 g/cm 3 .…”

“…Critical optical characteristics for radiation detection include the excitation and emission wavelengths, refractive indices, and light attenuation lengths [3][4][5]. State-of-the-art refining methods produce aromatic ring polymers with high purity [6].…”

Undoped Polycarbonate for Detection of Environmental Radiation

“…4 Excitation and emission spectra for PC. The excitation spectrum was acquired at the 350-nm emission maximum, and the emission spectrum was monitored at the 310-nm excitation maximum.…”

“…Aromatic ring polymers doped with various uorescent guest molecules have been used in radiation detectors as scintillation materials for many years. [1][2][3][4][5] The guest molecules convert the radiation-induced ultra-violet emission of the polymers into easily detected visible light.…”

Position Dependence for Count Rates in a Polyethylene Naphthalate Survey Meter

“…[7][8][9][10][11][12][13][14][15] We have previously developed a scintillation substrate from common polyethylene naphthalate (PEN), and evaluated its overall performances for radiation detection.…”