Ternary cadmium sulphide selenide quantum dots as new scintillation materials

Monodisperse, highly luminescent, zinc blende, cadmium sulphide selenide (CdSxSe1-x, x=mole fraction of sulphur) quantum dots (QDs) were prepared in gram scales in the particle size range 2?6-4?3 nm. With the varying S and Se contents, emission wavelengths of CdSxSe1-x QDs were tuned from 439 to 581 nm (?exc.=370 nm). QDs were well dispersed in organic solvents and optically transparent plastic scintillators made with up to 10 wt-%QDs in polyvinyltoluene (PVT) were prepared. The result from alpha particle detection indicated the wavelengths match with the sensitivity of the photomultiplier tube. Pulse height peaks of CdSxSe1-x with the wavelength of emission from 439 to 482 nm, appeared around 0?35 (channel no./amplifier gain), with different photon counts. No pulse height peak was observed with QDs that emitted at 505 nm or longer wavelengths. Under studied conditions, CdS0?95Se0?05 was found to be the most efficient scintillator.