Dielectric matrix imposed stress–strain effect on photoluminescence of Ge nanocrystals

Ge nanocrystals embedded in SiO2 and Lu2O3 matrices were fabricated using the pulsed laser deposition method and investigated using high-resolution transmission electron microscopy, X-ray diffractometry and photoluminescence spectroscopy. X-ray diffractometry and Fullprof computer program clearly revealed the bond lengths of Ge nanocrystals embedded in Lu2O3 matrix is smaller than that in SiO2 matrix, which can be attributed to the greater compressive stress exerted on Ge nanocrystals by the Lu2O3 matrix. The greater compressive stress will lead to much more defects induced at the interface of Ge nanocrystals and thus enhance the intensity of photoluminescence. The findings presented here indicate that the matrix environment of the nanocrystals plays a significant role in the photoluminescence property.