Impact of carrier redistribution on the photoluminescence of CdTe self-assembled quantum dot ensembles

Quasi-Stranski–Krastanow growth mode of self-assembled CdTe quantum dots grown on ZnSe by molecular beam epitaxy

“…The PL intensity at 2.633 eV (or 2.755 eV) includes wetting layer emission and the dots with the small size. The fast decay is attributed to the wetting layer emission, and the slow decay is related to the emission from the dots [9]. The decay time is longer in group-I than in group-II because of the type-II band alignment of the ZnTe-like wetting layer, which is determined by smaller spatial overlap between the hole and electron wavefunctions.…”

“…Much of the research in this area has focused on II-VI SAQDs, CdSe/ZnSe [1][2][3][4][5], ZnTe/ZnSe [6,7] and CdTe/ZnTe [8][9][10] SAQDs, whose lattice mismatches are approximately 7%. Their growth modes are confirmed to be Stranski-Krastanow (SK) growth mode, implying that a two-dimensional wetting-layer is present between the dots and the matrix.…”

Effect of the barrier width on the cathodoluminescence spectra in the strained CdTe/ZnTe superlattices with quantum dot layers

“…Also the sample with CdTe layer thickness of 1.5 ml and ZnTe layer thickness of 100 ml was prepared. Morphology of these samples was studied on TEM in [4,2]. Average diameter of fully developed CdTe QDs equals 3 nm while their density approaches 10 12 cm -2 .…”

“…For QDs made of II-VI semiconductor compounds such as CdSe/ZnSe or CdTe/ZnTe the growth starts from randomly distributed 2D platelets, which serve as precursors for the QD growth. Results of scanning transmission electron microscopy (TEM) show that both 2D-like and 3D-like objects exist simultaneously if thickness of CdTe (CdSe) deposited on ZnTe (ZnSe) substrate is less than 2.5 ml [2,3]. With a further increase of the amount of QD material an ensemble of fully developed 3D QDs, that are isolated from each other, is formed, and no uniform wetting layer (WL) is present.…”

Evolution of crystalline domain size and epitaxial orientation of CdTe/Si(111) quantum dots

“…5,6 The first studies on self-assembled CdTe islands date from 1996 and up to now almost all are concentrated in the ZnTe/CdTe system, which also follows the SK mode, although recent studies have shown that the II-VI compounds follow a modified SK mode, with a nonuniform or discontinuous wetting layer. 7,8 Self-assembled QDs of II-VI compounds are also very attractive due to the possibility of magnetic ions incorporation and the promise for performing logic operations using electron spins. 9,10 In this context the use of Si as substrate material has many advantages in comparison with GaAs, in spite the difficulties imposed by a very big lattice mismatch of 19.82%, and is an obvious goal due to its mechanical strength, low price and compatibility with standard Si-based device processing.…”