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Shallow Donors (shallow + donor)

Distribution by Scientific Domains
Physics and Astronomy100%

Selected Abstracts

Vertical Bridgman growth and annealing effect of Bi doped ZnSe single crystal

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 10 2004
C. B. Oh
Abstract In order to prepare p-type ZnSe, bismuth (Bi) as an acceptor dopant was doped into ZnSe single crystal by vertical Bridgman method. Photoluminescence (PL) spectra measured at 4.2 K on as-grown crystal showed the strong shallow donor,acceptor pair (DsAP) emission, deep donor,acceptor pair (DdAP) emission and weak I1Bi emission line. To enhance the activation ratio of Bi in ZnSe single crystals, ZnSe:Bi was annealed in saturated zinc and selenium atmosphere at different temperatures. In the case of annealing in the range of 700,800 °C, DdAP emission disappeared and the intensities of DsAP and I1Bi emission relatively increased. From the dependence of PL spectra on excitation light intensity and the temperature, the acceptor activation energy and deep donor level were estimated about 103 meV and 34 meV, respectively. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Relationship between grain-boundary capacitance and bulk shallow donors in SnO2 polycrystalline semiconductor

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 7 2008
P. R. Bueno
Abstract The relationship between grain-boundary capacitance and extrinsic shallow donors caused by Nb addition to SnO2·CoO binary polycrystalline system has been investigated by means of combined techniques such as I ,V characteristic response, complex impedance and capacitance analysis and electrostatic force microscopy. The estimated role of the Nb doping is to increase the concentration of shallow donors that are capable of enhancing the electronic donation to grain-boundary acceptors. This effect leads to the formation of potential barriers at grain boundaries with a simultaneous increase of grain-boundary capacitance and non-Ohmic features of the polycrystalline device doped with Nb atoms. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Electrical properties of bulk n-ZnO single crystals under hydrostatic pressure

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 3 2009
I. K. Kamilov
Abstract Pressure dependences of Hall coefficient RH(P) and resistivity , (P) have been measured for n-ZnO bulk crystals with impurity concentration Ni = 1017,1018 cm,3 and concentration of free electrons ,1017 cm,3 at T = 300 K at hydrostatic pressures up to P = 25 GPa. It has been found that the exponential increase of RH(P) and , (P), observed in the vicinity of the polymorphous transition PPH = 9 GPa, is caused by the increase of ionization energy of shallow donors. At P > PPH, a step-like decrease of the resistivity has been observed, indicating a phase transition from diamond structure to NaCl-type structure. In accordance with formulas derived from the ,heterophase structure , effective medium' model, phase volume fractions in the critical region of the polymorphous transformation have been calculated and the threshold values of normalized effective resistivity have been determined. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Light-induced neutralization of hydrogen shallow donors in zinc oxide

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 8 2006
N. H. Nickel
Abstract Infrared absorption measurements of the O,H shallow donor complex in zinc oxide show that its vibrational mode is very sensitive to sub band-gap illumination. Upon illumination the intensity of the O,H vibrational line exhibits a pronounced decrease. This effect is completely reversible. Annealing the specimens at temperatures above 30 K restores the O,H vibrational line. The decrease and increase of the O,H absorption line is caused by a change of the infrared effective charge due to neutralization and ionization, respectively, of H shallow donors. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]