Lu, Xuguang
Published in
Journal of Statistical Physics
For nonsoft potential collision kernels with angular cutoff, we prove that under the initial condition f0(v)(1+|v|2+|logf0(v)|)∈L1(R3), the classical formal entropy identity holds for all nonnegative solutions of the spatially homogeneous Boltzmann equation in the class L∞([0, ∞); L12(R3))∩C1([0, ∞); L1(R3)) [where L1s(R3)={f∣f(v)(1+|v|2)s/2∈L1(R3)...
jb, li xia, jb
We have studied the hole levels and exciton states in CdS nanocrystals by using the hole effective-mass Hamiltonian for wurtzite structure. It is found that the optically passive P-x state will become the ground hole state for small CdS quantum dots of radius less than 69 Angstrom. It suggests that the "dark exciton" would be more easily observed i...
liu, hy wang, xd wu, j xu, b wei, yq jiang, wh ding, d xl, ye lin, f zhang, jf
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Optical and structural investigations of InAs quantum dots (QDs) covered by InxGa1-xAs (0 less than or equal to x less than or equal to 0.3) overgrowth layer have been systematically reported. The decrease of strain in the growth direction of InAs quantum dots covered by InGaAs layer instead of GaAs is demonstrated by transmission electron microsco...
wang, xd niu, zc feng, sl
Optical and structural properties of self-organized InAs/GaAs quantum dots (QDs) with InxGa1-xAs or GaAs cover layers grown by molecular beam epitaxy (MBE) have been characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM) and photoluminescence (PL) measurements. The TEM and AFM images show that the surface stress of t...
liu, hy wang, xd xu, b ding, d jiang, wh wu, j wang, zg
We have studied the optical and structural properties of InAs/GaAs QDs covered by InxGa1-xAs (0 less than or equal to x less than or equal to 0.3) layer using transmission electron microscopy, photoluminescence (PL) spectra and atomic force microscopy. We find that the strain reduces in the growth direction of InAs islands covered by InGaAs instead...
wang, ls fong, wk surya, c cheah, kw zheng, wh wang, zg
We report the investigation of temperature and excitation power dependence in photoluminescence spectroscopy measured in Mg-doped GaN epitaxial layers grown on sapphire by metalorganic chemical vapor deposition, The objective is to examine the effects of rapid-thermal annealing on Mg-related emissions. It is observed that the peak position of the 2...
xl, xu liu, ht shi, cs zhao, yw fung, s beling, cd
In our recent report, [Xu , Appl. Phys. Lett. 76, 152 (2000)], profile distributions of five elements in the GaN/sapphire system have been obtained using secondary ion-mass spectroscopy. The results suggested that a thin degenerate n(+) layer at the interface is the main source of the n-type conductivity for the whole film. The further studies in t...
wang, xd niu, zc feng, sl miao, zh
We report the effect of InchiGa1-chiAs (0 less than or equal to chi less than or equal to0.4) capping layer on photoluminescence (PL) properties of 1.3 mum wavelength self-assembled InAs quantum islands, which are formed via depositing 3.5 monolayers (ML) InAs on GaAs (1 0 0) substrate by molecular beam epitaxy (MBE). Compared with the InchiGa1-chi...
lw, lu yan, h yang, cl xie, mh wang, zg wang, j wk, ge
A detailed study of the characteristics of undoped GaN films, grown on either vicinal or nominal flat SiC (0001) substrates by molecular beam epitaxy, has been carried out using photoluminescence and Raman scattering techniques. The I I K photoluminescence spectra of the GaN film grown on the vicinal SiC (0001) substrate show a strong and sharp nea...
liao, my chai, cl yang, sy liu, zk qin, fg wang, zg
Carbon films with an open-ended structure were obtained by mass-selected ion-beam deposition technique at 800degreesC. Raman spectra show that these films are mainly sp(2)-bonded. In our case, threshold ion energy of 140 eV was found for the formation of such surface morphology. High deposition temperature and ion-beam current density are also resp...
