Showing papers by "Dinesh K. Sharma published in 1989"
TL;DR: In this article, the temperature dependence of forward and reverse currents of a Si:Ge:H•Pd barrier was investigated and it was shown that the diode quality factor is 2 and is independent of temperature.
Abstract: In this paper, we have investigated the temperature dependence of forward and reverse currents of a‐Si:Ge:H‐Pd barriers. In contrast to a‐Si:H, we find that the diode quality factor is 2 and is independent of temperature. We have confirmed quantitatively that the forward current is recombination limited and the reverse current is generation limited. The barrier height ΦB=0.7 eV, which is half the measured optical gap. The frequency, bias, and temperature dependence of capacitance have also been investigated. From the capacitance measurements, we infer that the density of states near midgap is approximately 2×1017 cm−3 eV−1.
12 citations
TL;DR: In this article, deep-level admittance spectroscopy (DLAS) of DLAS of DX centers in AlxGa1−xAs:Sn (0.2 0.35) was used to reveal all the levels observed by DLAS and provided information only on the SN3 level.
Abstract: Deep‐level admittance spectroscopy (DLAS) of DX centers in AlxGa1−xAs:Sn (0.2 0.35 because of the strong freeze‐out of free carriers in these samples. Even in the case of low AlAs mole fraction samples (x<0.35), the DLTS technique fails to reveal all the levels observed by DLAS and provides information only on the SN3 level.
9 citations
TL;DR: In this article, photoluminescence and Hall measurements on Ge doped InGaAs layers lattice matched to InP were reported, with the highest Ge content sample giving a p type conductivity with carrier concentration of 5 ×1017 cm-3.
Abstract: Photoluminescence and Hall measurements are reported on Ge doped InGaAs layers lattice matched to InP. Ge doping of these samples results in highly compensated material, with the highest Ge content sample giving a p type conductivity with carrier concentration of 5 ×1017 cm-3. Low temperature PL spectra of these samples show a broad peak from 0.55 to 0.77 eV due to Ge. The peak of luminescence shifts to lower energy with increasing Ge content. The peak position shifts to higher energy with increasing excitation like in a D-A pair transition. The PL spectra have been explained on the basis of a model which assumes tail states near the band edges due to disorder produced by the presence of Ge in the lattice.
TL;DR: In this paper, a high intensity luminescence band between 0.9 and 1.03 eV was observed in the samples with dual implantation of boron and phosphorus.
Abstract: Photoluminescence measurements on silicon implanted with boron, phosphorus, and dual implanted with phosphorus and boron are reported. A high intensity luminescence band between 0.9–1.03 eV is observed in the samples with dual implantation of boron and phosphorus. The luminescence band has similar spectral characteristics as that of the 1.018 eV W or II band which is observed in silicon samples irradiated with neutrons or ions. However the annealing behaviour of the luminescence band observed in our samples differs considerably from that of the W band, whose intensity increases on annealing at 525 K and is quenched on heating to 600 K. The luminescence band in our samples is not annealed out even at 900 C. The temperature dependence of the intensity of the luminescence band is also studied. It shows excitonic behaviour with an activation energy of 52 meV.