Glasses doped with PbS nanocrystals

Abstract 5.74Na2O–21.38B2O3–72.88SiO2 glasses doped with semiconductor 1% wt PbS nanocrystals were fabricated via a sol–gel route. The formation of PbS nanocrystals in the glass matrix was proven by X-ray photoelectron spectroscopy (XPS). The HRTEM images showed that the PbS crystals existed as nanocrystals with a narrow distribution diameter at 3.5 nm. Furthermore, Fast Fourier transformation (FFT) demonstrated the existence of PbS with face-centered cubic (FCC) structure. Comparing with the bulk PbS, the absorption edge in the optical absorption spectra of the glass doped with PbS nanocrystals exhibited a blue shift with an obvious quantum size effect. The glass had a nonlinear refractive index (γ) of −2.03 × 10−14 cm2/GW and a nonlinear absorption coefficient (β) of 7.05 × 10−10 cm/GW) based on Z-scan technique measurement.