Band gap and polarizability of boro-tellurite glass: Influence of erbium ions

Structural and luminescence behaviour of Er3+ doped telluro-fluoroborate glasses

“…The higher phonon energy of the telluro-borate glasses leads to have non-radiative emission by multiphonon relaxation and narrow down its applications [7]. In order to overcome this difficulty low phonon energy fluoride content was additionally added into the telluro-borate glasses which in turn enhance the radiative emission of the Er 3+ ions by reducing the non-radiative relaxation [8].…”

Optical, Physical and Structural Properties of Er3+ Doped Low‐Phonon Energy Vitreous Matrix: ZnO‐B2O3‐TeO2

“…The optical band gap is an intrinsic property of a material that governs the other properties of the material like electrical properties and absorption of light. The optical band gap (direct and indirect band gap) values in the present study have been determined by applying the relation proposed by Davis and Mott given in Equation where, B is a constant related to the extent of band tailing, E opt is the optical energy gap, hυ is photon energy, α(υ) is the absorption coefficient, n is the index number ( n = 2 for indirect transitions and n = 1/2 for direct transitions).…”

“…Addition of rare earth ions to TeO 2 glass results in breakage of TeOTe and BOB bond linkages and thus resulting in systematic conversion of TeO 4 to TeO 3 structural groups via formation of TeO 3+1 units as well as BO 3 units. This also results in the formation of non‐bridging oxygens (NBOs) . Since NBOs bind an excited electron less tightly than bridging oxygens, the NBOs are more polarizable than bridging oxygens .…”

“…B 2 O 3 is added in the present system because of its glass forming ability, good rare earth ion solubility, and hardness . Since, ZnO can occupy both network forming and network modifying positions in borate and tellurite glasses, therefore it can act as a useful modifier that increases the rigidity of the network, glass forming range and stability, lowers the viscosity and improves the transparency to make the glasses less prone to moisture …”

“…Earlier research on fiber lasers and fiber amplifiers was based on silica and fluoride based glasses, however the former suffer from their intrinsic high phonon energy whereas the latter has poor stability and chemical durability. There are many studies on tellurite glasses doped with different rare earths and modifiers however the literature reporting optical, structural and physical studies of Er 3+ doped boro‐tellurite glasses is scarce …”