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Daniel Macdonald - One of the best experts on this subject based on the ideXlab platform.
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doping dependence of the carrier lifetime crossover point upon dissociation of iron boron pairs in crystalline silicon
Applied Physics Letters, 2006Co-Authors: Daniel Macdonald, Thorsten Trupke, Thomas Roth, P N K Deenapanray, R A BardosAbstract:The excess carrier density at which the carrier lifetime in crystalline silicon remains unchanged after dissociating iron-boron pairs, known as the crossover point, is reported as a function of the boron dopant concentration. Modeling this doping dependence with the Shockley-Read-Hall model does not require knowledge of the iron concentration and suggests a possible refinement of reported values of the capture cross sections for electrons and holes of the Acceptor Level of iron-boron pairs. In addition, photoluminescence-based measurements were found to offer some distinct advantages over traditional photoconductance-based techniques in determining recombination parameters from low-injection carrier lifetimes.
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electronic properties of iron boron pairs in crystalline silicon by temperature and injection Level dependent lifetime measurements
Journal of Applied Physics, 2005Co-Authors: Jens E Birkholz, Daniel Macdonald, Karsten Bothe, Jan SchmidtAbstract:Iron-boron pairs in crystalline silicon are studied by measuring the recombination lifetime as a function of injection density, doping concentration, and temperature. The characteristic crossover point of the injection-Level-dependent carrier lifetime curves measured before and after optical dissociation of the iron-boron pairs is analyzed to determine the energy Level as well as the electronand hole-capture cross sections of the Acceptor Level of iron-boron pairs, assuming known recombination parameters for interstitial iron. The doping concentration dependence of the crossover point gives an electron-capture cross section of s1.4± 0.2 d 3 10 ˛14 cm 2 , while the temperature dependence results in a hole-capture cross section in the range from 0.5 3 10 ˛15 to 2.5 3 10 ˛15 cm 2 and an energy Level of s0.26± 0.02 d eV below the conduction-band edge. © 2005 American Institute of Physics . fDOI: 10.1063/1.1897489g
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capture cross sections of the Acceptor Level of iron boron pairs in p type silicon by injection Level dependent lifetime measurements
Journal of Applied Physics, 2001Co-Authors: Daniel Macdonald, Andres Cuevas, J WongleungAbstract:Injection-Level dependent recombination lifetime measurements of iron-diffused, boron-doped silicon wafers of different resistivities are used to determine the electron and hole capture cross sections of the Acceptor Level of iron–boron pairs in silicon. The relative populations of iron–boron pairs and interstitial iron were varied by exposing the samples to different Levels of illumination prior to lifetime measurements. The components of the effective lifetime due to interstitial iron and iron–boron pairs were then modeled with Shockley–Read–Hall statistics. By forcing the sum of the modeled iron–boron and interstitial iron concentrations to equal the implanted iron dose, in conjunction with the strong dependence of the shape of the lifetime curves on dopant density, the electron and hole capture cross sections of the Acceptor Level of iron–boron pairs have been determined as (3±2)×10−14 cm−2 and (2±1)×10−15 cm−2.
M D Mccluskey - One of the best experts on this subject based on the ideXlab platform.
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formation of isolated zn vacancies in zno single crystals by absorption of ultraviolet radiation a combined study using positron annihilation photoluminescence and mass spectroscopy
Physical Review Letters, 2013Co-Authors: Enamul H Khan, Marc Weber, M D MccluskeyAbstract:: Positron annihilation spectra reveal isolated zinc vacancy (V(Zn)) creation in single-crystal ZnO exposed to 193-nm radiation at 100 mJ/cm(2) fluence. The appearance of a photoluminescence excitation peak at 3.18 eV in irradiated ZnO is attributed to an electronic transition from the V(Zn) Acceptor Level at ~100 meV to the conduction band. The observed V(Zn) density profile and hyperthermal Zn(+) ion emission support zinc vacancy-interstitial Frenkel pair creation by exciting a wide 6.34 eV Zn-O antibonding state at 193-nm photon-a novel photoelectronic process for controlled V(Zn) creation in ZnO.
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formation of isolated zn vacancies in zno single crystals by absorption of ultraviolet radiation a combined study using positron annihilation photoluminescence and mass spectroscopy
Physical Review Letters, 2013Co-Authors: Enamul H Khan, Marc H Weber, M D MccluskeyAbstract:Positron annihilation spectra reveal isolated zinc vacancy (${V}_{\mathrm{Zn}}$) creation in single-crystal ZnO exposed to 193-nm radiation at $100\text{ }\text{ }\mathrm{mJ}/{\mathrm{cm}}^{2}$ fluence. The appearance of a photoluminescence excitation peak at 3.18 eV in irradiated ZnO is attributed to an electronic transition from the ${V}_{\mathrm{Zn}}$ Acceptor Level at $\ensuremath{\sim}100\text{ }\text{ }\mathrm{meV}$ to the conduction band. The observed ${V}_{\mathrm{Zn}}$ density profile and hyperthermal ${\mathrm{Zn}}^{+}$ ion emission support zinc vacancy-interstitial Frenkel pair creation by exciting a wide 6.34 eV Zn-O antibonding state at 193-nm photon---a novel photoelectronic process for controlled ${V}_{\mathrm{Zn}}$ creation in ZnO.
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cu doping of zno by nuclear transmutation
Applied Physics Letters, 2011Co-Authors: F A Selim, M C Tarun, Donald Wall, L A Boatner, M D MccluskeyAbstract:Zinc oxide single crystals were doped with copper Acceptors by means of the nuclear transmutation doping method, which gives highly uniform dopant distributions and has a much higher probability of controlling the dopant locations in the lattice. The Cu doping was confirmed by the infrared absorption signature of Cu2+ at 5780 cm−1. Hall-effect measurements were performed to study the effect of CuZn on the electrical properties of ZnO. These measurements indicated that the Cu Acceptor Level lies 0.160 eV below the conduction-band minimum.
B. J. Skromme - One of the best experts on this subject based on the ideXlab platform.
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optical spectroscopy of si related donor and Acceptor Levels in si doped gan grown by hydride vapor phase epitaxy
Applied Physics Letters, 1998Co-Authors: J Jayapalan, B. J. Skromme, R P Vaudo, V M PhanseAbstract:The optical properties of n-type GaN grown by hydride vapor phase epitaxy, with intentional Si doping Levels ranging from nominally undoped to ND−NA=4×1017 cm−3, are investigated using low temperature photoluminescence. We identify free and neutral donor-bound exciton transitions and two-electron satellites (TES) at 1.7 K. The energy difference between the principal neutral donor-bound exciton peak and its TES yields a Si donor binding energy of 22 meV. The intensity of the Si-related TES increases with increasing Si concentration. The Si donor is much shallower than the two residual donors, which have binding energies of 28 and 34 meV. This result suggests that the main residual donors in this material (and possibly in many layers grown by metal organic chemical vapor deposition and metal organic molecular beam epitaxy as well) are not Si. Silicon doping also introduces an Acceptor Level with a binding energy of about 224 meV.
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properties of the shallow o related Acceptor Level in znse
Journal of Applied Physics, 1995Co-Authors: J Chen, B. J. Skromme, Yonghang Zhang, Katsuhiro Akimoto, S J PachutaAbstract:Zinc selenide layers grown by molecular beam epitaxy (MBE) and doped with ZnO have been characterized using low temperature photoluminescence (PL) measurements as a function of excitation Level, temperature, and laser energy (i.e., selectively excited donor‐Acceptor pair luminescence or SPL), as well as reflectance measurements. An O‐related donor‐to‐Acceptor (D0−A0) pair band is clearly observed in all of the ZnO‐doped layers, whose position varies from 2.7196 to 2.7304 eV, depending on the excitation Level. The same peak occurs in a number of undoped, As‐doped, and Ga‐doped MBE samples, showing that O can occur as a residual impurity. Temperature‐dependent measurements reveal the existence of a corresponding conduction band‐to‐Acceptor (e−A0) peak at 2.7372 eV (39.8 K), confirming the existence of the Acceptor Level. The binding energy of this Acceptor is about 84±2 meV, which is 27 meV shallower than that of N. The SPL measurements reveal four excited states of the shallow Acceptor Level, separated fro...
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properties of the as related shallow Acceptor Level in heteroepitaxial znse grown by molecular beam epitaxy
Physical Review B, 1993Co-Authors: Yonghang Zhang, B. J. Skromme, S M A Shibli, Maria C. TamargoAbstract:The As-related shallow Acceptor Level in ZnSe is characterized in detail by low- and variable-temperature photoluminescence (PL), selective-pair luminescence, and magnetospectroscopy measurements, using intentionally As-doped material grown by molecular-beam epitaxy on GaAs. The shallow-Acceptor-related PL features grow progressively stronger with ${\mathrm{Zn}}_{3}$${\mathrm{As}}_{2}$ flux, while deep-Level peaks at 2.20 and 1.7 eV are observed only at the highest doping Levels. In addition to the previously reported donor-to-Acceptor peak at about 2.693\char21{}2.697 eV, we observe a corresponding band-to-Acceptor peak at temperatures of \ensuremath{\sim}25 K and above. The temperature dependence of the band-Acceptor peak position yields a light-hole-Acceptor binding energy of 114.6\ifmmode\pm\else\textpm\fi{}0.7 meV for thermally strained material, which compares to values of 114.1\ifmmode\pm\else\textpm\fi{}0.4 and 113.0\ifmmode\pm\else\textpm\fi{}0.6 meV we recently obtained in the same way for Li and N Acceptors, respectively. The corresponding value for unstrained material is calculated to be ${\mathit{E}}_{\mathit{A}}^{\mathrm{As}}$=114.8\ifmmode\pm\else\textpm\fi{}0.7 meV.
Adisak Boonchun - One of the best experts on this subject based on the ideXlab platform.
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identification of a n related shallow Acceptor and electron paramagnetic resonance center in zno n 2 on the zn site
Physical Review B, 2013Co-Authors: Walter R L Lambrecht, Adisak BoonchunAbstract:First-principles calculations of N${}_{2}$ in ZnO located on the Zn site show that this defect is a shallow double Acceptor and can be identified with a N-related shallow Level observed experimentally by donor-Acceptor-pair recombination. When the shallow Acceptor Level is occupied with a single electron, it can also explain a N${}_{2}$-related electron paramagnetic resonance signal observed in ZnO. We show that the $g$ factor and hyperfine structure observed for this center are closer to those of a N${}_{2}{}^{+}$ radical than to a N${}_{2}^{\ensuremath{-}}$ radical as previously proposed in literature and hence consistent with the Zn location.
J Wongleung - One of the best experts on this subject based on the ideXlab platform.
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capture cross sections of the Acceptor Level of iron boron pairs in p type silicon by injection Level dependent lifetime measurements
Journal of Applied Physics, 2001Co-Authors: Daniel Macdonald, Andres Cuevas, J WongleungAbstract:Injection-Level dependent recombination lifetime measurements of iron-diffused, boron-doped silicon wafers of different resistivities are used to determine the electron and hole capture cross sections of the Acceptor Level of iron–boron pairs in silicon. The relative populations of iron–boron pairs and interstitial iron were varied by exposing the samples to different Levels of illumination prior to lifetime measurements. The components of the effective lifetime due to interstitial iron and iron–boron pairs were then modeled with Shockley–Read–Hall statistics. By forcing the sum of the modeled iron–boron and interstitial iron concentrations to equal the implanted iron dose, in conjunction with the strong dependence of the shape of the lifetime curves on dopant density, the electron and hole capture cross sections of the Acceptor Level of iron–boron pairs have been determined as (3±2)×10−14 cm−2 and (2±1)×10−15 cm−2.
