Band gap tuning of PbSe quantum dots by SrO addition in silicate glasses

Abstract

Lead selenide (PbSe) quantum dots (QDs) doped with Sr2+ were precipitated in silicate glasses. The absorption and photoluminescence (PL) bands of the glasses blue-shifted as SrO concentration increased. These changes resulted mainly because Sr incorporation increased the band gap of PbSe nanocrystals. After heat treatment at 520 degrees C for 10 h, mean QD diameters were similar before and after the addition of SrO: similar to 7.2 nm with 0% SrO and similar to 6.9 nm with 10 mol% SrO. However, these two glasses show the absorption bands at 1743 nm and 1246 nm, and PL bands at 1803 and 1370 nm, respectively. These large shifts are due to the increase in the band gap through the formation of Pb1 - x,SrxSe mixed-type QDs. One typical chemical composition of QDs formed in a glass with 10 mol% Sr0 after heat treatment at 520 degrees C for 10 his Pb0.89Sr0.11Se with a band gap of similar to 0.58 eV. (C) 2016 Elsevier B.V. All rights reserved.