Green, red and near-infrared photon up-conversion in Ga–Ge–Sb–S:Er3+ amorphous chalcogenides

Abstract

We report on compositional tuning in Et3+ ions doped Ga-Ge-Sb-S glassy system allowing for effective H-2(11/2) -> I-4(15/2) (530 nm), S-4(3/2) -> I-4(15/2) (550 nm), F-4(9/2) -> I-4(15/2) (660 mm), I-4(9/2) -> I-4(15/2) ( 810 nm), I-4(11/2) -> I-4(15/2) (990 nm) intra-4f electronic transition emissions of Er3+ ions under 808 nm, 980 nm or 1550 nm laser pumping. We changed the composition of well-known Ge20Ga5Sb10S65 glass to Ge25Ga10-xSbxS65, where x=0.5 at%, 2.5 at% or 5.0 at% and doped it with 0.5 at% of Er3+ ions. The short-wavelength absorption edge of the studied glassy hosts is blue-shifted by substitution of Sb with Ga to similar to 500 nm making the green emission at 530 nm and 550 nm and even 495 nm (F-4(7/2)-> I-4(15/2)) observable, while the glass stability was kept high characterized with the difference of T-c-T-g>100 K and mean coordination numbers 2.67-2.71. Up-conversion emission decay times of all anti-Stokes emissions were in the range of 0.2-2.1 ms. The influence of Ga substitution with Sb on the structure and the optical properties was investigated. The spectroscopic parameters for Er3+ ions with local environment change were analyzed based on Judd-Ofelt theory. (C) 2013 Elsevier B.V. All rights reserved.