کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1497342 | 993002 | 2008 | 6 صفحه PDF | دانلود رایگان |
The nanocomposite consisting of PbS quantum dots with average diameter of 26 Å and polyvinyl alcohol was characterized using photoluminescence and far-infrared spectroscopy. Photoluminescence spectra of nanocomposite, measured in temperature range from 8 to 280 K, consists of broad peak which spans the energy range from 1.2 to 2.1 eV and can be connected with trap states inside the band gap. Far-infrared measurements are consistent with theoretical calculations that include mechanical boundary conditions at the quantum dot – host interface. Observed peak at 90 cm−1 can be assigned to coupled modes with lp = 1, while broad peak at 275 cm−1 is above any lattice frequency and is close to sum of the frequencies of the lp = 0 acoustic and lp = 0 coupled optical mode of PbS quantum dots.
Journal: Optical Materials - Volume 30, Issue 7, March 2008, Pages 1177–1182