We have numerically investigated the vibrational spectra of amorphous single-component clusters for several types of interactions among the particles. For all the potentials we have studied, we find that the density of states can be described, except at the two ends of the spectrum, by the same functional form to a very good approximation, and that the fluctuation properties of the spectra in this central region converge to those of the Gaussian orthogonal ensemble of random matrices with increasing system size. We conjecture that this scenario is true for a broad class of potentials.

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An analytical model for tunnel barrier modulation in triple metal double gate tunnel FET is presented for the first time in this paper. Three different metals over the channel region assist to form a barrier in the channel which restricts the reverse tunneling of the carrier, i.e., tunneling from drain to source. The choice of three metals with different work functions helps to increase the ON-current and also to form a barrier in the channel, which reduces the OFF-current. The surface potential and the electric field are analytically modeled by solving 2-D Poisson's equation and Kane's model is used to calculate the tunneling current. The analytical results are verified with SILVACO ATLAS simulated results. Index Terms-Ambipolar behavior, band-to-band tunneling, Poisson's equation, tunnel FET (TFET), work function.Navjeet Bagga is currently pursuing the M.E. degree with the

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An effective BSF is a key structural element for an efficient solar cell, either in a multi-junction or in a single-junction device. In this paper, two important materials AlGaAs and InAlGaP with their varied thickness (i.e. 0.05-1.0) μm both for top BSF and bottom BSF cells are investigated using the computational numerical modeling TCAD tool Silvaco ATLAS. It has been found that under the current matching condition with the relatively thinner (30 nm) top BSF layer and the thicker (1,000 nm) bottom BSF layer, the cell exhibit an overall enhancement of short-circuit current density J sc and open circuit voltage Voc thereby improving the overall efficiency of the cell. A wide band gap material In 0.5 (Al 0.7 Ga 0.3 ) 0.5 P is proved to be a better choice for both window and BSF layer by increasing 6.2% more efficiency than using other widely used Al 0.7 Ga 0.3 As material under the same cell configuration because of its high photo generation rate. For this optimized cell structure, the maximum J sc = 16.10 mA/cm 2 , V oc = 2.392 V, and fill factor = 87.52% are obtained under AM1.5G illumination, exhibiting a maximum conversion efficiency of 32.1964% (1 sun) and 36.6781% (1,000 suns). This work reports the Influence of different BSF material and structures on the characteristics and efficiency of Multi-Junction solar cells. The detail photo-generation rates and EQE in this optimized ARC less DJ solar cell structure are also observed. The major stages of the modeling are explained and the simulation results are validated with published experimental data to demonstrate the accuracy of our results produced by the model utilizing this technique.

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