Stark effect and polarizability in a single CdSe/ZnSe quantum dot

Abstract

The quantum-confined Stark effect in a single self-assembled CdSe/ZnSe quantum dot was studied by means of highly spatially resolved photoluminescence spectroscopy. A nanotechnological approach making use of a capacitor-like geometry enabled us to apply a well-defined lateral electric field on the quantum dots. Stark shifts of up to 1.1 meV were obtained, which can be well fitted by a purely quadratic dependence on an electric field. In quite good agreement with theoretical calculations, an exciton polarizability of 4.9×10−3 meV/(kV/cm)2 can be extracted, while the permanent dipole moment in the lateral direction is found to be negligible.

Progress in the optical studies of single InGaN/GaN quantum dots

“…The fit gives a lateral component of the polarizability = -1.45×10 -3 meV(kV) -2 cm 2 or 20.7 nm 3 in cgs units. This value is of the same order as that obtained for CdSe/ZnSe QDs [56]. It leads to a characteristic lateral dimension of the QD of 2.7 nm which is consistent with the value inferred below from the analysis of the linewidth broadening.…”

“…The effects of both lateral and vertical applied electric fields with respect to the QD plane have been studied in several QD structures [54][55][56]. However, only a few recent studies have reported such measurements on GaN/AlN [57,58] and InGaN/GaN QDs [59,60].…”

Anticrossings in Förster coupled quantum dots

“…This has been observed experimentally in a range of QD systems including InGaAs/GaAs, 29 GaAs/GaAlAs, 30 and CdSe/ZnSe. 31 Furthermore, a theoretical study of an eight-band strain dependent k · p Hamiltonian has shown that the quadratic dependence of the ground-state energy on applied field is a good approximation for largely truncated self-assembled quantum dots, although the approximation becomes worse as the dot size increases in the growth direction. 32 …”

Quantum Dot Blueing and Blinking Enables Fluorescence Nanoscopy

“…29,30 Upon exposure to oxygen, selenium surface atoms of a CdSe core are photooxidized, creating an evaporating SeO 2 surface film which causes the nanocrystal to degrade over time 31 ( Figure 2A). The increased confinement of excitons broadens the energetic gap between their valence and conduction bands and irreversibly blue shifts their emission wavelength.…”