Photoacoustic spectra on Mn-doped zinc silicate powders by evacuated sealed silica tube method

The non-radiative transition processes on nondoped Zn2SiO4 and Zn2SiO4:Mn powders with various Mn concentrations were studied by photoacoustic (PA) spectroscopy. Zn2SiO4:Mnx powders were prepared by dry reaction within an evacuated silica glass tube. As the result of photoluminescence (PL) measurement, the increase of PL intensity for green emission on samples doped with Mn between 1% and 6% and the concentration quenching for luminescence on samples doped with Mn between 7% and 12% were confirmed. For the green luminescence on zinc silicate doped with Mn phosphor, the PL decay behavior is assumed to be due to tunneling directly from excited states of electron traps to the excited states of Mn-ion. TheMncontent dependence of PL intensity for green emission is well interpreted by tunneling theory and the results of PA spectra, that is, the green emission is assisted by tunneling from nonradiative levels of Mn-ion to luminescencet level as 4T1(4G).