With attention to the thin film structure of colloidal quantum dot solar cells, in this paper in order to improvement of active layer absorption of them, we have proposed the use of nanostructure pattern for enhancement of their performance. For this purpose we have presented suitable nano hemisphare patterns in colloidal quantum dot solar cells for light trapping in absorption layer. Then with...

We propose a quantum-dot version of the quantumwell cascade laser of Faist et al. The elimination of single phonon decays by the three-dimensional confinement implies a several order-of-magnitude reduction in the threshold current. The requirements on dot size (10–20 nm) and on dot density and uniformity [one coupled pair of dots per (200 nm3) with 5% nonuniformity] are close to current technol...

Articles you may be interested in The electronic properties of a two-electron multi-shell quantum dot-quantum well heterostructure Enhanced tunnel transport in disordered carbon superlattice structures incorporated with nitrogen Nonlinear transport in quantum-cascade lasers: The role of electric-field domain formation for the laser characteristics Electrical conductivity enhanced dielectric and...

The first self-assembled InAs quantum dash lasers grown by molecular beam epitaxy on InP (001) substrates are reported. Pulsed room-temperature operation demonstrates wavelengths from 1.60 to 1.66 μm for one-, three-, and five-stack designs, a threshold current density as low as 410 A/cm2 for single-stack uncoated lasers, and a distinctly quantum-wire-like dependence of the threshold current on...

In this study graphene oxide (GO) was synthesized by using Hummer’s method. Low dimension graphene quantum dot nanoparticles (GQDs) were synthesized using pulse laser irradiation. Fourier Transform-Infrared Spectroscopy (FTIR), Ultraviolet-Visible (UV-Vis) spectroscopy and photoluminescence (PL) analysis were applied to study the GQDs characteristic. Scanning electron microscopy illustrated the...

We propose a quantum tweezer for extracting a desired number of neutral atoms from a reservoir. A trapped Bose-Einstein condensate is used as the reservoir, taking advantage of its coherent nature, which can guarantee a constant outcome. The tweezer is an attractive quantum dot, which may be generated by red-detuned laser light. By moving at certain speeds, the dot can extract a desired number ...

We report the experimental observation of photon antibunching in the photoluminescence of a chemically synthesized CdSe/ZnS quantum dot (QD) at room temperature and from a single selfassembled InAs/GaAs QD at 4 K. These results prove that a single quantum dot acts like an artificial atom, with a discrete anharmonic spectrum. Using the quantum regression theorem, we find that the normalized seco...

We coherently probe a quantum dot that is strongly coupled to a photonic crystal nano-cavity by scattering of a resonant laser beam. The coupled system’s response is highly nonlinear as the quantum dot saturates with nearly one photon per cavity lifetime. This system enables large amplitude and phase shifts of a signal beam via a control beam, both at single photon levels. We demonstrate photon...

The resonance frequency of an InAs quantum dot strongly coupled to a GaAs photonic-crystal cavity was electrically controlled via the quadratic quantum confined Stark effect. Stark shifts up to 0.3 meV were achieved using a lateral Schottky electrode that created a local depletion region at the location of the quantum dot. We report switching of a probe laser coherently coupled to the cavity up...

The authors have determined both the real and imaginary parts of the dielectric polarizability of a single quantum dot. The experiment is based on the observation and the manipulation of Rayleigh scattering at photon frequencies near the resonance of an optical exciton transition in single self-assembled InAs and InGaAs quantum dots. The interference between the narrow-band laser field and the ...