in this paper we propose and simulate a new heterostructure mesfet, called δ-doped ldd hmesfet. to improve carrier velocity in vicinity of the source in channel of gaas mesfet, one can replace source with alxga 1-x as. by increasing al content, discontinuity of hetero-interface could be increased. therefore, the velocity increases in the low field. however, increasing al mole fraction in excess...

Heterostructure field-effect transistor design criteria are proposed in this study. GaAs pseudomorphic high electron mobility transistors (pHEMTs) are extensively applied to radar satellite receipt dispatcher antenna, and cell phone. Devices for various doped type and different material heterostructure are simulated and analyzed. The δ-doped InGaP/InGaAs/GaAs pHEMT with high density of two dime...

We study the electronic structure of a new type of Fibonacci superlattice based on Si δ-doped GaAs. Assuming that δ-doped layers are equally spaced, quasiperiodicity is introduced by selecting two different donor concentrations and arranging them according to the Fibonacci series along the growth direction. The one-electron potential due to δ-doping is obtained by means of the Thomas-Fermi appr...

In this research Bi2O3 was doped with mixtures of 8, 10, 12 and 18 mol % of Y2O3 and Yb2O3 to stabilizing the δ-Bi2O3 phase using solid state reaction technique. Experimental samples were fabricated by isostatic pressing and sintering at 850 °C for 24 h. X-ray diffraction analysis detected cubic phase (δ-Bi2O3) as the sole stable crystalline phase in samples including 12 and 18 mol % of Y2O3 an...

We report resonant electronic Raman scattering in optimally doped single layer HgBa2CuO4+δ (Hg-1201) and trilayer HgBa2Ca2Cu3O8+δ (Hg-1223) single crystals. Analysis of the B1g and B2g channels in the superconducting state of Hg-1201 advocates for a gap having d-wave symmetry. In addition a resonant study B1g pair-breaking peak and the A1g peak suggests that the A1g peak is not directly related...

P-type doping in high Al-content AlGaN alloys is a main challenge for realizing AlGaN-based deep ultraviolet optoelectronics devices. According to the first-principles calculations, Mg activation energy may be reduced so that a high hole concentration can be obtained by introducing nanoscale (AlN)5/(GaN)1 superlattice (SL) in Al0.83Ga0.17N disorder alloy. In this work, experimental evidences we...

Semiconductor nanoparticles are studied worldwide at present because of their good optical, physical and chemical properties. In this research work, a set of Zn doped cadmium oxide (Cd1-xZnxO1-δ) nanoparticles were synthesized by simple chemical precipitation route. The precursor materials used in this research work were cadmium nitrate and zinc nitrate (as basic materials) and sodium hydroxide...

Samples of GaAs 8-doped with beryllium have been studied with photoluminescence. With a lightly doped sample, (2 x 1016 Be atoms per m2) a spectral feature is observed which can be interpreted as caused by radiative recombinations between spatially non-confined conductionband electrons and acceptor-related holes forming a miniband system confined spatially to the &doped region. With higher dens...