Fig. 2: Photophysical characteristics of CdSe-ZnSe sg-QD ensembles with varying core-shell geometries.
From: Strain-graded quantum dots with spectrally pure, stable and polarized emission
a Absorption spectra and (b), PL spectra of CdSe (r = 2.5 nm)-ZnSe sg-QDs with varying shell thicknesses (0 nm ≤ H ≤ 5.0 nm). Arrows in (a) and shading in (b) indicate optical transitions between |1SHX> and |g > (red) and |1SLX> and |g > (blue). c Peak PL energy of CdSe-ZnSe sg-QDs with varying core radii (2.0 nm ≤ r ≤ 4.0 nm) and shell thicknesses (0 nm ≤ H ≤ 5.0 nm) (upper panel), and estimated changes in the bulk band gap (ΔEg,Bulk) of CdSe (middle panel) and the effective compressive strain (β*) (lower panel) developed in CdSe core upon ZnSe shell growth. d Heavy hole-light hole energy split (ΔEsplit), e radiative recombination time for single exciton (τX) and (f), ensemble emission linewidth of CdSe-ZnSe sg-QDs with varying core radii (2.0 nm ≤ r ≤ 4.0 nm) as a function of the effective compressive strain imposed by ZnSe of varying shell thicknesses (0 nm ≤ H ≤ 5.0 nm). More sample information is provided in Supplementary Fig. 12.
