相关论文: A First-Principles Study of CdSe Nanoclusters Capp…
A first-principles study of small CdnSen Quantum Dots (QD) ('n' =6, 12, 13, and 33) has been performed for application to QD solar cell development. We separately assess the effects of the particle size and the passivating ligands upon the…
Recent experiments have probed the chiral properties of semiconductor nanocrystal (NC) quantum dots (QDs), but understanding the circular dichroism lineshape, excitonic features, and ligand induction mechanism remains a challenge. We…
The influence of ligands on the low frequency vibration of different thicknesses cadmium selenide colloidal nanoplatelets is investigated using resonant low frequency Raman scattering. The strong vibration frequency shifts induced by ligand…
It is widely accepted that the properties of most semiconductor nanocrystals can be tuned by their core size, shape and material. In covalent semiconductor nanocrystal materials, such as silicon, germanium or carbon, certain degree of…
Unique optical properties of colloidal semiconductor quantum dots (QDs), arising from quantum mechanical confinement of charge within these structures, present a versatile testbed for the study of how high electric fields affect the…
The atomic and electronic structure of a set of proposed thin (1.6 nm in diameter) silicon/silica quantum nanodots and nanowires with narrow interface, as well as parent metastable silicon structures (1.2 nm in diameter), was studied in…
Adsorption of small ligands on semiconductor surfaces is a possible route to modify these surfaces so that they can be used in biosensing and optoelectronic devices. In this work we perform density-functional theory calculations of…
Binary compositions of surface ligands are known to improve the colloidal stability and fluorescence quantum yield of nanocrystals (NCs), due to ligand-ligand interactions and surface organization. Herein, we follow the thermodynamics of a…
Luminescent colloidal CdSe nanorings are a new type of semiconductor structure that have attracted interest due to the potential for unique physics arising from their non-trivial toroidal shape. However, the exciton properties and dynamics…
We considered modification of the defect density of states in CdTe as influenced by a buffer layer in ZnO(ZnS, SnSe)/CdS/CdTe solar cells. Compared to the solar cells employing ZnO buffer layers, implementation of ZnSe and ZnS resulted in…
Cu(In,Ga)Se2 (CIGSe)-based solar cells are promising candidates for efficient sunlight harvesting. However, their complex composition and microstructure can change under operation conditions, for instance heating from sun light illumination…
Atomically thin two-dimensional semiconducting transition metal dichalcogenides (TMDs) can withstand large levels of strain before their irreversible damage occurs. This unique property offers a promising route for control of the optical…
Non-trivial electronic states are attracting intense attention in low-dimensional physics. Though chirality has been identified in charge states with a scalar order parameter, its intertwining with charge density waves (CDW), film thickness…
Traditional concentrating photovoltaic (CPV) systems utilize multijunction cells to minimize thermalization losses, but cannot efficiently capture diffuse sunlight, which contributes to a high levelized cost of energy (LCOE) and limits…
Cr 2p core excited XAS and XMCD spectra of ferromagnetic Cr$_{1-\delta}$Te with several concentrations of $\delta$=0.11-0.33 and ferrimagnetic Cr$_{5}$S$_{6}$ have been measured. The observed XMCD lineshapes are found to very weakly depend…
We report on a systematic study of the Cd, Zn, Se, and S elemental distributions across the interfaces in CdSe/Cd1-xZnxS core-shell and CdSe/CdS/Cd1-xZnxS core-crown-shell quantum wells with the CdSe core thickness ranging from 3.5 to 5.5…
The exciton states of strained CdTe/CdS core-shell tetrapod-shaped nanocrystals were theoretically investigated by the numerical diagonalization of a configuration interaction Hamiltonian based on the single-band effective mass…
Positron Two Dimensional Angular Correlation of Annihilation Radiation (2D-ACAR) measurements reveal modifications of the electronic structure and composition at the surfaces of PbSe quantum dots (QDs), deposited as thin films, produced by…
Structural and charge relaxation of nanoclusters of CdSe of diameter 1-2 nm are studied with first principle calculations. The relaxations cause significant distortions of smaller systems of ~ 1 nm in diameter and have very minimal effect…
I present first principles calculations of the phonon dispersions of TiSe$_2$ in the $P\overline{3}c1$ phase, which is the currently accepted low-temperature structure of this material. They show weak instabilities in the acoustic branches…