Quantum Confined DC Stark Effect in Microcrystallites

Abstract

This paper reports on the electric field induced absorption change in the situation of zero-dimensional quantum confinement. We have studied CdS rnicrocrystallites embedded in glass by a sensitive modulation spectroscopy technique at room temperature. We observe a two-line spectrum and a quadratic dependence on the applied field. This absorption change is related to the Stark shift of the lowest electron-hole pair state of the quantum dot.Auf der Basis modulationsspektroskopischer Transmissionsmessungen an CdS-Mikrokristallitglasern bei Raumtemperatur wird der EinfluB eines elektrischen Feldes auf die Absorption eines quasinull-dimensionalen Systems untersucht. Das beobachtete Zweilinienspektrum und die dem Quadrat der Feldstarke proportionale Absorptionsanderung werden der Starkverschiebung des Elektron-LochPaar-Grundzustandes zugeordnet.

Electrooptical constants in spherical quantum dots

“…The corresponding electrooptical function (20) was defined as a function of the electron-hole mass ratio (J, the dimensionless parameter t , and the reduced laser frequency 8. We demonstrated that the electrooptical constants A E~ and A E~ show an F2 behaviour for small electric field, in agreement with previous published results, and a quasilinear character with F in the strong-field regime.…”

Size-dependent photo-induced shift of the first exciton band in CdTe quantum dots in glass prepared by a two-stage heat-treatment process

“…The nanocrystal within the electric field of trapped charges will have a red shifted Gaussian absorption band as in electroabsorption spectra reported for CdS x Se 1Àx nanoparticles in glass in previous studies [27][28][29]. The electric field-induced shift DE in the ground state Gaussian absorption band calculated in strong confinement limit (neglecting Coulomb effects) from second-order perturbation theory is given by [14,30] DE ðmeVÞ ¼ À24 Â 10 À7 M½F ðkV=cmÞ 2 ½R ave ðnmÞ 4 ,…”

Quantum lens in an external electric field: Anomalous photoluminescence behavior

“…Several works have been devoted to study, both experimentally and theoretically, the optical and electrical properties of quantum pyramids, [3][4][5][6][7][8][9] quantum disks, 10 spherical quantum dots, [11][12][13] and quantum lenses. 14 -21 Also, experimental and theoretical studies when an external electric field is present have been performed in quantum wells, 22 quantum disks, 23 quantum pyramids, 24 cuboidal nanocrystal, 25 hemispherical quantum dots, 26 spherical quantum dots, [27][28][29] self-assembled quantum dots, [30][31][32][33][34][35] and with an arbitrary geometry. 36 These studies cover relevant topics such as electron and hole states, photoluminescence and photocurrent measurements.…”