Low-temperature luminescence of lead silicate glass

Abstract

Abstract-The temperature quenching of intrinsic luminescence of a lead silicate glass of the 20PbO ⋅ 80SiO 2 composition has been investigated in the temperature range 7-200 K. It has been found that the temperature behavior of the intensity of intrinsic luminescence does not obey the well known Mott's law for intracenter quenching of luminescence but is adequately described by the empirical Street's formula. It has been dem onstrated that, with allowance made for the disorder of the atomic structure, the experimental temperature dependence of the luminescence intensity of the glass can be represented as a superposition of Mott's depen dences for an ensemble of local luminescence centers. The obtained distribution of luminescence centers over the activation energies of quenching has an asymmetric form with prevailing low energy states. It has been assumed that this feature has a general character and, at low temperatures, determines the specificity of the processes of nonradiative relaxation of the electronic subsystem for many oxide glasses.

An intrinsic luminescence in binary lead silicate glasses

“…Since the quenching centers with the same activation energy are usually the subject to the ratio of Mott, so to analyze the origin and mechanisms of luminescence suppression is advisable to use an approach proposed in Refs. [18,19]. Under this approach, the expression for I L (T) can be represented as:…”

“…where I M 0 is an intensity at T = 10 K, p M -characteristic parameter, E a -activation energy, k -Boltzmann constant, and g(E a ) -distribution function of emission centers depending on the activation energy [18]:…”

The relation between static disorder and photoluminescence quenching law in glasses: A numerical technique

“…It is worthy of note that distributions obtained for lead-silicate glasses fall quite rapidly with growing activation energy [3]. Moreover, low-energy luminescent centers affect mainly low-temperature quenching points leading to deviation from Eq.…”

“…The values of E 0 and w were chosen close to those derived from experiment [3]. Firstly the initial data for Eq.…”

“…However luminescence investigations in the most popular temperature range (80-300 K) cannot provide unambiguous choice between different photoluminescence quenching models [3]. Liquid helium temperatures freeze out phonon modes and thus significantly lower the degree of dynamic disorder which rises from atoms thermal motion.…”