Efficient plastic scintillators utilizing phosphorescent dopants.

We demonstrate improved light yield from plastic scintillators utilizing a phosphorescent dopant to collect both singlet and triplet excitations created by ionizing radiation. We specifically considered poly(vinyltoluene) and poly(9-vinylcarbazole) doped with an Ir phosphor. We present the spectral, temporal, and integrated yield response as a function of dopant concentration to pulses of 10 keV electrons. Both doped plastics yield a maximum light output $\sim$ 200{\%} of anthracene with decay times $<$ 850 ns. High light yield was obtained for Ir element fractions up to $\sim $ 10 wt{\%} implying that these scintillators may be useful for gamma detection.