Carrier multiplication-the generation of multiple electron-hole pairs by a single photon-is currently of great interest for the development of highly efficient photovoltaics. We study the effects of infilling PbSe quantum-dot solids with metal oxides by atomic layer deposition on carrier multiplication. Using time-resolved microwave conductivity measurements, we find, for the first time, that c...

Colloidal quantum dot solids combine convenient solution-processing with quantum size effect tuning, offering avenues to high-efficiency multijunction cells based on a single materials synthesis and processing platform. The highest-performing colloidal quantum dot rectifying devices reported to date have relied on a junction between a quantum-tuned absorber and a bulk material (e.g., TiO(2)); h...

Semiconductor self-assembled quantum dots form a three dimensional confinement for charge carriers in the solid state matrix. The confinement modifies the density of states, leading to atom like optical properties of quantum dots that can be studied by absorption or emission of photons. Due to the sharp resonance lines that are observed in optical spectra, quantum dots are often referred to as ...

In a coupled quantum-dot-nanocavity system, the photoluminescence from an off-resonance cavity mode exhibits strong quantum correlations with the quantum-dot transitions, even though its autocorrelation function is classical. Using new pump-power dependent photon-correlation measurements, we demonstrate that this seemingly contradictory observation that has so far defied an explanation stems fr...

Coherent acoustic phonons in PbS quantum dots are observed using femtosecond optical techniques. This is the first observation of coherent acoustic phonons in a semiconductor quantum dot; the phonons are generated through the deformation-potential coupling to the quantum-dot exciton. The acoustic modes are weakly damped, and we also find extremely weak coupling (S , 0.01) to the optical modes. ...

In this paper, we analyze the performance of an electro-optic modulator based on a single quantum dot strongly coupled to a nano-resonator, where electrical control of the quantum dot frequency is achieved via quantum confined Stark effect. Using realistic system parameters, we show that modulation speeds of a few tens of GHz are achievable with this system, while the energy per switching opera...

We have performed a numerical simulation of a system made of a quantum dot and a nearby quantum point contact deened, by means of depleting metal gates, in a two-dimensional electron gas at a GaAs/AlGaAs heterointerface. As recent experiment have shown, such a system can be used as a non-invasive detector of single charges being added to or removed from a quantum dot. We have computed the occup...

We study the injection mechanism of a single electron from a static quantum dot into a moving quantum dot. The moving quantum dots are created with surface acoustic waves (SAWs) in a long depleted channel. We demonstrate that the injection process is characterized by an activation law with a threshold that depends on the SAW amplitude and on the dot-channel potential gradient. By sufficiently i...

Based on the Keldysh nonequilibrium Green function (NGF) technique, a general formula for the current and transmission coefficient through a one dimensional quantum dot lattice is derived without the consideration of electron-electron interactions. We obtain an analytical condition for complete resonant transmission when the levels of dots are aligned, which depends on the parity of the number ...

Spin exchange between a single-electron charged quantum dot and itinerant electrons leads to an emergence of Kondo correlations. When the quantum dot is driven resonantly by weak laser light, the resulting emission spectrum allows for a direct probe of these correlations. In the opposite limit of vanishing exchange interaction and strong laser drive, the quantum dot exhibits coherent oscillatio...