N-structure based on InAs/AlSb/GaSb superlattice photodetectors

Turan, Raşit
We have studied the theoretical and experimental properties of InAs/AlSb/GaSb based type-II superlattice (T2SL) pin photodetector called N-structure. Electronic properties of the superlattice such as HH-LH splitting energies was investigated using first principles calculations taking into account InSb and AlAs as possible interface transition alloys between AlSb/InAs layers and individual layer thicknesses of GaSb and InAs. T2SL N-structure was optimized to operate as a MWIR detector based on these theoretical approaches tailoring the band gap and HH-LH splitting energies with InSb transition layers between InAs/AlSb interfaces. Experimental results show that AlSb layers in the structure act as carrier blocking barriers reducing the dark current. Dark current density and RoA product at 125 K were obtained as 1.8 x 10(-6) A cm(-2) and 800 Omega cm(2) at zero bias, respectively. The specific detectivity was measured as 3 x 10(12) Jones with cut-off wavelengths of 4.3 mu m at 79 K reaching to 2 x 10(9) Jones and 4.5 mu m at 255 K.


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In the present study, the molecular orbital properties of 1,3-dipolar cycloaddition products of 1-methyl-3-oxidopyridinium betaine with C-70 have been investigated theoretically at the level of PM3 (RHF) type semi empirical quantum chemical calculations and then single point DFT calculations were performed for the energies. The betaine acts as a 4 pi-component across its 2,6-positions and certain C=C bonds of C-70 act as 2 pi-component in the 1,3-dipolar cycloadditions considered presently. Various cycloadd...
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Okan, SE; Akbas, H; Aktas, S; Tomak, Mehmet (Elsevier BV, 2000-09-01)
We present a variational method to compute the binding energies of helium-like impurities in finite parabolic GaAs-Ga1-xAlxAs quantum wells. The effects of band nonparabolicity in the conduction band are taken into account within the effective mass approximation. The dependence of the impurity binding energy on the applied electric field and the impurity position is also discussed together with the polarization effect for all cases. (C) 2000 Academic Press.
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Polad, S.; Erkoç, Şakir (American Scientific Publishers, 2011-04-01)
We have calculated the optimized geometries, electronic structures and spin distributions of metal and non-metal elements Li, Na, N and P doped C60 fullerene dimers and trimers with different spin multiplicities using hybrid density functional theory (DFT) at the B3LYP/6-31G level of theory. Natural population analysis and Mulliken population analysis show that non-metal elements (N, P) inside the C60 fullerene dimers and trimers are well isolated and preserve their electronic structures while charge transf...
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The effects of an applied electric field on subband energies and excitonic binding for a graded GaAlAs quantum well are calculated variationally within the effective mass approximation. The very sensitive dependence of subband energies on the applied field is calculated using a model potential profile and exact electron and hole wavefunctions. Our calculations have revealed the dependence of the energy shifts of subbands, and excitonic binding on the field direction in the graded quantum well. This permits ...
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The O(N) and parallelization techniques have been successfully applied in tight-binding molecular-dynamics simulations of single-walled carbon nanotubes (SWNT's) of various chiralities. The accuracy of the O(N) description is found to be enhanced by the use of basis functions of neighboring atoms (buffer). The importance of buffer size in evaluating the simulation time, total energy, and force values together with electronic temperature has been shown. Finally, through the local density of state results, th...
Citation Formats
M. HOŞTUT et al., “N-structure based on InAs/AlSb/GaSb superlattice photodetectors,” SUPERLATTICES AND MICROSTRUCTURES, pp. 116–122, 2015, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/34575.