Related papers: Size Dependence of the Multiple Exciton Generation…
We address recent experiments (Science 325, 1367 (2009)) reporting on highly efficient multiplication of electron-hole pairs in carbon nanotube photodiodes at photon energies near the carrier multiplication threshold (twice the…
The distribution of rates of carrier multiplication (CM) following photon absorption is calculated for semiconductor nanocrystals (NCs). The NC electronic structure is described using a screened pseudopotential method known to give reliable…
Carrier Multiplication (CM) is a Coulomb-driven non-radiative recombination mechanism which leads to the generation of multiple electron-hole pairs after absorption of a single high-energy photon. Recently a new CM process, termed space…
Spatially indirect Type-II band alignment in magnetically-doped quantum dot (QD) structures provides unexplored opportunities to control the magnetic interaction between carrier wavefunction in the QD and magnetic impurities. Unlike the…
Using resonantly excited photoluminescence along with photoluminescence excitation spectroscopies, we study the carrier excitation processes in CdTe/ZnTe and CdSe/ZnSe self-assembled quantum dots. Photoluminescence excitation spectra of…
A quantum-kinetic approach to the ultrafast dynamics of carrier multiplication in semiconductor quantum dots is presented. We investigate the underlying dynamics in the electronic subband occupations and the time-resolved optical emission…
Electron transfer to an individual quantum dot promotes the formation of charged excitons with enhanced recombination pathways and reduced lifetimes. Excitons with only one or two extra charges have been observed and exploited for very…
Carrier multiplication (CM), where the absorption of a single photon results in the generation of several electron-hole pairs via impact ionization, plays a pivotal role in the quest for enhancing the performance of solar cells beyond the…
We report here an assessment of carrier multiplication (CM) yields in PbSe and PbS nanocrystals (NCs) by a quantitative analysis of biexciton and exciton dynamics in transient photoluminescence decays. Interest in CM, the generation of more…
We present a spectroscopic study of excitation dynamics in self assembled CdTe/ZnTe quantum dots. Insight into details of kinetics is obtained from the time resolved micro-photoluminescence, single photon correlation and subpicosecond…
Cd(Se,Te) Quantum Dots (QD) in ZnSe barrier typically exhibit a very high spectral density, which precludes investigation of single dot photoluminescence. We design, grow and study individual Cd(Se,Te)/ZnSe QDs of low spectral density of…
We study carrier interaction induced many-body effects on the excitonic optical properties of highly photoexcited one-dimensional semiconductor quantum wire systems by solving the dynamically screened Bethe-Salpeter equation using realistic…
Upon photo- or electrical-excitation, colloidal quantum dots (QDs) are often found in multi-carrier states due to multi-photon absorption and photo-charging of the QDs. While many of these multi-carrier states are observed in single-dot…
A natural explanation for the carrier concentration-dependent electronic behavior in the layered cobaltates emerges within correlated-electron Hamiltonians with finite on-site and significant nearest neighbor hole-hole Coulomb repulsions.…
Incorporation of manganese impurities into II-VI semiconductors results in a dramatic change in their properties due to strong exchange interactions between the Mn ion and the semiconductor host. In colloidal quantum dots (QDs), these…
Multiple exciton generation is a process in which more than one electron hole pair is generated per absorbed photon. It allows us to increase the efficiency of solar energy harvesting. Experimental studies have shown the multiple exciton…
Fulfilling the potential of the colloidal semiconductor quantum dots (QDs) in electrically driven applications remains a challenge largely since operation of such devices involves charged QDs with drastically different photo-physical…
We applied low temperature diffraction limited confocal optical microscopy to spatially resolve, and spectroscopically study photoluminescence from single self-assembled semiconductor quantum dots. Using selective wavelength imaging we…
Exciton binding energy and electron-hole recombination probability are presented as the two important metrics for investigating effect of dot size on electron-hole interaction in CdSe quantum dots. Direct computation of electron-hole…
Colloidal semiconductor nanoplatelets combine weak lateral confinement with strong Coulomb interactions, enhanced by dielectric confinement. When the platelets are charged with carriers of the same sign, this results in severe Coulomb…