Search results for " Germanium"
showing 10 items of 37 documents
Spectroscopic studies of neutron-deficient light nuclei: decay properties of 21Mg, 25Si and 26P
2003
Neutron‐deficient nuclei with Tz equals to −3/2 and −2 have been produced at the GANIL/LISE3 facility in fragmentation reactions of a 95 MeV/u 36Ar primary beam in a 12C target. For the first time, β‐delayed proton and β‐γ emission has been simultaneously observed in the decay of 21Mg, 25Si and 26P. The decay scheme of the latter is proposed and the Gamow‐Teller strength distribution in its β decay is compared to shell‐model calculations based on the USD interaction. The B(GT) values derived from the absolute measurement of the β‐branching ratios are in agreement with the quenching factor of about 60% obtained for allowed Gamow‐Teller transitions in this mass region. A precise half‐life of …
Transient photoresponse and incident power dependence of high-efficiency germanium quantum dot photodetectors
2012
We report a systematic study of time-resolved and power-dependent photoresponse in high-efficiency germanium quantum dot photodetectors (Ge-QD PDs), with internal quantum efficiencies greater than 100 over a broad wavelength, reverse bias, and incident power range. Turn-on and turn-off response times (τ on and τ off) are shown to depend on series resistance, bias, optical power, and thickness (W QD) of the Ge-QD layer, with measured τ off values down to ∼40 ns. Two different photoconduction regimes are observed at low and high reverse bias, with a transition around -3 V. A transient current overshoot phenomenon is also observed, which depends on bias and illumination power. © 2012 American …
Hydrogen-Related Paramagnetic Centers in Ge-Doped Sol-Gel Silica Induced by γ-Ray Irradiation
2006
We have studied the generation mechanisms of H(II) paramagnetic centers in Ge-doped silica by investigating up to 104 mol ppm sol-gel Ge-doped silica materials. We have considered materials with the same concentrations of Ge but that are produced by two different densification routes that give rise to different concentrations of Ge-related oxygen deficient centers (GeODC(II)). These centers are characterized by an optical absorption band at ∼5.2 eV (B2 β band) and two related emissions at ∼3.2 eV and ∼4.3 eV. The GeODC(II) content was estimated by absorption and emission measurements. The H(II) centers were induced by room temperature γ-ray irradiation and their concentration was determined…
Role of Ge nanoclusters in the performance of photodetectors compatible with Si technology
2013
In this work, we investigate the spectral response of metal-oxide- semiconductor photodetectors based on Ge nanoclusters (NCs) embedded in a silicon dioxide (SiO2) matrix. The role of Ge NC size and density on the spectral response was evaluated by comparing the performance of PDs based on either densely packed arrays of 2 nm-diameter NCs or a more sparse array of 8 nm-diameter Ge NCs. Our Ge NC photodetectors exhibit a high spectral responsivity in the 500-1000 nm range with internal quantum efficiency of ~ 700% at - 10 V, and with NC array parameters such as NC density and size playing a crucial role in the photoconductive gain and response time. We find that the configuration with a more…
Room-temperature efficient light detection by amorphous Ge quantum wells
2013
In this work, ultrathin amorphous Ge films (2 to 30 nm in thickness) embedded in SiO2 layers were grown by magnetron sputtering and employed as proficient light sensitizer in photodetector devices. A noteworthy modification of the visible photon absorption is evidenced due to quantum confinement effects which cause both a blueshift (from 0.8 to 1.8 eV) in the bandgap and an enhancement (up to three times) in the optical oscillator strength of confined carriers. The reported quantum confinement effects have been exploited to enhance light detection by Ge quantum wells, as demonstrated by photodetectors with an internal quantum efficiency of 70%. © 2013 Cosentino et al.
Production of refractory elements close to the Z=N line using the ion-guide technique
1998
Production of neutron-deficient isotopes of refractory elements in the A = 80-88 region was studied using the IGISOL technique and the 165 MeV Si-32 + Ni-nat reaction. Radioactive isotopes of Y through Mo could be produced up to the M-T = + 1 line. New information on the decay of the A = 82 and 85 nuclei, including a more detailed decay scheme and more accurate half-life for Y-82, was obtained. (C) 1998 Elsevier Science B.V. All rights reserved.
β decay studies of n-rich Cs isotopes with the ISOLDE Decay Station
2017
R. Lica et al. -- 14 pags., 7 figs., tab. -- Open Access funded by Creative Commons Atribution Licence 3.0
AGATA-Advanced GAmma Tracking Array
2012
WOS: 000300864200005
Evidence for violation of the Gallagher-Moszkowski rules in154Pm
1972
The existence of two radioactive species of154Pm (1.8 min ground state and 2.65 min isomer) is established. The Nilsson model configurations assigned to these states give evidence against the validity of the Gallagher-Moszkowski coupling rules in154Pm.