4,354 research outputs found
A long-wavelength infrared photodetector with self-organized InAs quantum dots embedded on HEMT-like structure
No full textWe fabricated a quantum dot infrared photodetector (QDIP) with 5-stacked self-organized InAs quantum dots embedded in a high electron mobility transistor-like modulation doped structure and utilize lateral electron transport. A peak response of the QDIP appeared at lambda = 10.5 mu m at T = 80 K. We also found that the device exhibits bias-dependent responsivity
Estimation of depth and 3D motion parameters of moving objects with multiple stereo images by using Kalman filter
No full textRemoval of trichloroethylene by cometabolic transformation and activated carbon adsorption using two-stage methanotrophic treatment system
No full textEnhanced quanum-confined Stark effect of vertically-coupled quantum dots at room temperature
No full textRoom Temperature Operation Long-Wavelength Infrared Photodetector with Self-Assembled InAs Quantum Dots
No full textRoom temperature far infrared (8 similar to 10 mu m) photodetectors using self-assembled InAs quantum dots with high detectivity
No full textA room temperature operation of far-infrared detectors made of self-assembled quantum dots embedded in the channel region of modulation-doped heterostructures is demonstrated. At room temperature, the detector shows a low dark current ranging in the nano-amperes at a bias voltage of 10 V. After the optimization of the separation between the quantum dot region and the 2DEG, a peak responsivity of 5.3 A/W is obtained at 9.0 mu m. The high detectivities of 6 x 10(8) and 5 x 10(10) cmHz(1/2)/W are obtained at room temperature and 80 K, respectively
Direct observation of strong quantum-confined stark effect in vertically-stacked quantum dots at room temperature
No full textStrong quantum-confined Stark effect of vertically-stacked quantum dots (VSQDs) is observed by electroabsorption spec troscopy at room temperature. Contrary to single-layer QDs, the VSQDs show a large red shift of 9.4 meV with electric-field change of 60 kV/cm
First-principles study of the equilibrium structures of Si-n clusters
No full textWe investigate the atomic structure of Si-n (n = 9-14) clusters using the first-principles pseudopotential method within the local-density-functional approximation (LDA). The equilibrium geometries of small clusters with n less than or equal to 12 tend to be capped prismatic structures. For n = 13, we find a surface-like metallic compact structure which is derived from a capped icosahedron and competes with a stable trigonal prism, while this structure is the most stable for n = 14. These results are compatible with the observed stability of Si-13 and Si-14, as compared to Si-n clusters with nearby Values of n, against chemical reactions with simple molecules. The effect of electron-electron correlations on the energetics of isomers with n = 13 is examined through variational quantum Monte Carlo calculations, and the LDA energy ordering remains unchanged, consistently with previous diffusion quantum Monte Carlo calculations
- …
