@article{barletta_berkman_moody_el-masry_emara_reed_bedair_2007, title={Development of green, yellow, and amber light emitting diodes using InGaN multiple quantum well structures}, volume={90}, ISSN={["0003-6951"]}, DOI={10.1063/1.2721133}, abstractNote={The authors present optical and electrical data for long wavelength (573–601nm) InGaN∕GaN multiple quantum well light emitting diodes (LEDs) grown by metal organic chemical vapor deposition. These results are achieved by optimizing the active layer growth temperature and the quantum well width. Also, the p-GaN is grown at low temperature to avoid the disintegration of the InGaN quantum wells with high InN content. A redshift is observed for both the green and yellow LEDs upon decreasing the injection current at low current regime. In the case of the yellow LED, this shift is enough to push emission into the amber (601nm).}, number={15}, journal={APPLIED PHYSICS LETTERS}, author={Barletta, Philip T. and Berkman, E. Acar and Moody, Baxter F. and El-Masry, Nadia A. and Emara, Ahmed M. and Reed, Mason J. and Bedair, S. M.}, year={2007}, month={Apr} }
 @article{reed_arkun_berkman_elmasry_zavada_luen_reed_bedair_2005, title={Effect of doping on the magnetic properties of GaMnN: Fermi level engineering}, volume={86}, ISSN={["1077-3118"]}, DOI={10.1063/1.1881786}, abstractNote={GaMnN dilute magnetic semiconductor samples, prepared by metalorganic chemical vapor deposition, are shown to exhibit ferromagnetism or even paramagnetism depending upon the type and concentration of extrinsic impurity present in the film. In addition, GaMnN deposited using growth parameters normally yielding a nonferromagnetic film becomes strongly ferromagnetic with the addition of magnesium, an acceptor dopant. Based upon these observations, it seems that ferromagnetism in this material system depends on the relative position of the Mn energy band and the Fermi level within the GaMnN band gap. Only when the Fermi level closely coincides with the Mn-energy level is ferromagnetism achieved. By actively engineering the Fermi energy to be within or near the Mn energy band, room temperature ferromagnetism is realized.}, number={10}, journal={APPLIED PHYSICS LETTERS}, author={Reed, MJ and Arkun, FE and Berkman, EA and Elmasry, NA and Zavada, J and Luen, MO and Reed, ML and Bedair, SM}, year={2005}, month={Mar} }
 @article{arkun_reed_berkman_el-masry_zavada_reed_bedair_2004, title={Dependence of ferromagnetic properties on carrier transfer at GaMnN/GaN : Mg interface}, volume={85}, ISSN={["1077-3118"]}, DOI={10.1063/1.1810216}, abstractNote={We report on the dependence of ferromagnetic properties of metalorganic chemical vapor deposition grown GaMnN films on carrier transfer across adjacent layers. We found that the magnetic properties of GaMnN, as a part of GaMnN∕GaN:Mg heterostructures, depend on the thickness of both the GaMnN film and the adjacent GaN:Mg layer and on the presence of a wide band gap barrier at this interface. These results are explained based on the occupancy of the Mn energy band and how the occupancy can be altered due to carrier transfer at the GaMnN∕GaN:Mg interfaces.}, number={17}, journal={APPLIED PHYSICS LETTERS}, author={Arkun, FE and Reed, MJ and Berkman, EA and El-Masry, NA and Zavada, JM and Reed, ML and Bedair, SM}, year={2004}, month={Oct}, pages={3809–3811} }
 @article{reed_reed_jagannadham_verghese_bedair_el-masry_butler_2004, title={Electrical characterization of B-10 doped diamond irradiated with low thermal neutron fluence}, volume={22}, ISSN={["1520-8559"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-4344661941&partnerID=MN8TOARS}, DOI={10.1116/1.1763910}, abstractNote={A sample of B10 isotope doped diamond was neutron irradiated to a thermal fluence of 1.3×1019 neutron cm−2. The diamond sample was cooled continuously during irradiation in a nuclear reactor. Li7 is formed by nuclear transmutation reaction from B10. Characterization for electrical conductance in the temperature range of 160 K<T<600 K was performed on an unirradiated B10 doped sample and the B10 doped and irradiated sample. The unirradiated diamond sample showed p-type conductance at higher temperature (T>200 K) and p-type surface conductance at lower temperature (T<200 K). The irradiated sample showed decreasing conductance below 230 K and increasing conductance above 230 K with increasing temperature. Furthermore, the conductance showed a decrease above 400 K followed by an increase above 500 K. The observed behavior below 400 K with increase in temperature is interpreted in terms of compensation of surface p-type carriers by n-type bulk carriers generated from Li7 that is formed by nuclear transmutation reaction from B10 atoms. Also, compensation of n-type carriers from Li7 by p-type carriers from B10 is used to interpret the conductance above 400 K. A low concentration of radiation induced defects, absence of defect complexes, and the low activation energy of n-type Li7 are thought responsible for the observed variation of conductance in the irradiated diamond. The present results illustrate that neutron transmutation from B10 doped diamond is a useful method to achieve n-type conductivity in diamond.}, number={4}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A}, author={Reed, ML and Reed, MJ and Jagannadham, K and Verghese, K and Bedair, SM and El-Masry, N and Butler, JE}, year={2004}, pages={1191–1194} }
 @misc{roberts_parker_muth_leboeuf_aumer_bedair_reed_2002, title={Ultraviolet-visible metal-semiconductor-metal photodetectors fabricated from InxGa1-xN (0 <= x <= 0.13)}, volume={31}, number={1}, journal={Journal of Electronic Materials}, author={Roberts, J. C. and Parker, C. A. and Muth, J. F. and Leboeuf, S. F. and Aumer, M. E. and Bedair, S. M. and Reed, M. J.}, year={2002}, month={Jan}, pages={L1–6} }
 @article{reed_el-masry_stadelmaier_ritums_reed_parker_roberts_bedair_2001, title={Room temperature ferromagnetic properties of (Ga, Mn)N}, volume={79}, ISSN={["1077-3118"]}, DOI={10.1063/1.1419231}, abstractNote={Dilute magnetic semiconductor GaN with a Curie temperature above room temperature has been achieved by manganese doping. By varying the growth and annealing conditions of Mn-doped GaN we have identified Curie temperatures in the range of 228–370 K. These Mn-doped GaN films have ferromagnetic behavior with hysteresis curves showing a coercivity of 100–500 Oe. Structure characterization by x-ray diffraction and transmission electron microscopy indicated that the ferromagnetic properties are not a result of secondary magnetic phases.}, number={21}, journal={APPLIED PHYSICS LETTERS}, author={Reed, ML and El-Masry, NA and Stadelmaier, HH and Ritums, MK and Reed, MJ and Parker, CA and Roberts, JC and Bedair, SM}, year={2001}, month={Nov}, pages={3473–3475} }
 @article{reed_ritums_stadelmaier_reed_parker_bedair_el-masry_2001, title={Room temperature magnetic (Ga,Mn)N: a new material for spin electronic devices}, volume={51}, ISSN={["0167-577X"]}, DOI={10.1016/S0167-577X(01)00342-1}, abstractNote={A new dilute magnetic semiconductor (Ga,Mn)N grown by metal organic chemical vapor deposition (MOCVD) is reported. Vibrating sample magnetometer (VSM) and extraordinary Hall effect (EHE) measurements verified a ferromagnetic component at room temperature. The direction of the easy axis and the Curie temperature varies with the growth conditions, the latter ranging from 38°C to 75°C. Secondary ion mass spectroscopy (SIMS) confirms diffusion of Mn into the GaN to a depth of 380 Å.}, number={6}, journal={MATERIALS LETTERS}, author={Reed, ML and Ritums, MK and Stadelmaier, HH and Reed, MJ and Parker, CA and Bedair, SM and El-Masry, NA}, year={2001}, month={Dec}, pages={500–503} }
 @article{reed_el-masry_parker_roberts_bedair_2000, title={Critical layer thickness determination of GaN/InGaN/GaN double heterostructures}, volume={77}, DOI={10.1063/1.1334361}, abstractNote={We report on the critical layer thickness of GaN/InxGa1−xN/GaN double heterostructures in the composition range 0<x<0.16. The evolution of the photoluminescence spectra and the electrical properties of the InxGa1−xN well were monitored as its thickness was increased for a given % InN. Due to compressive stress and possible quantum-size effects, the emission energy from thin InGaN wells is blueshifted relative to thicker wells of a given % InN. The transition from the blueshifted emission of strained InGaN to redshifted emission of relaxed InGaN is also accompanied by dramatic changes in film conductivity and mobility. The thickness at which the onset of relaxation occurs is deemed the critical layer thickness of the InxGa1−xN film.}, number={25}, journal={Applied Physics Letters}, author={Reed, M. J. and El-Masry, N. A. and Parker, C. A. and Roberts, J. C. and Bedair, S. M.}, year={2000}, pages={4121–4123} }
 @article{hunter_reed_el-masry_roberts_bedair_2000, title={Epitaxial Y2O3 films grown on Si(111) by pulsed-laser ablation}, volume={76}, ISSN={["0003-6951"]}, DOI={10.1063/1.126217}, abstractNote={Y 2 O 3 has a relatively high dielectric constant (13–17) leading to several potential applications. In this work, pulsed-laser deposition was used to grow epitaxial Y2O3 films on Si(111) substrates. Structural characterization indicated two-dimensional growth without the formation of an amorphous interfacial layer. Annealing in either Ar or O2 was found to induce an O2 diffusion reaction resulting in the formation of two interfacial amorphous layers. Electrical characterization by capacitance–voltage and current–voltage indicated that the as-grown samples were poor insulating films. Annealing the samples improved the electrical performance by lowering leakage currents and exhibiting inversion during capacitance–voltage testing. This epitaxial growth points toward the possibility of the heteroepitaxial growth of silicon on insulator device structures.}, number={14}, journal={APPLIED PHYSICS LETTERS}, author={Hunter, ME and Reed, MJ and El-Masry, NA and Roberts, JC and Bedair, SM}, year={2000}, month={Apr}, pages={1935–1937} }
 @article{parker_roberts_bedair_reed_liu_el-masry_1999, title={Determination of the critical layer thickness in the InGaN/GaN heterostructures}, volume={75}, ISSN={["0003-6951"]}, DOI={10.1063/1.125146}, abstractNote={We present an approach to determine the critical layer thickness in the InxGa1−xN/GaN heterostructure based on the observed change in the photoluminescence emission as the InxGa1−xN film thickness increases. From the photoluminescence data, we identify the critical layer thickness as the thickness where a transition occurs from the strained to unstrained condition, which is accompanied by the appearance of deep level emission and a drop in band edge photoluminescence intensity. The optical data that indicate the onset of critical layer thickness, was also confirmed by the changes in InxGa1−xN surface morphology with thickness, and is consistent with x-ray diffraction measurements.}, number={18}, journal={APPLIED PHYSICS LETTERS}, author={Parker, CA and Roberts, JC and Bedair, SM and Reed, MJ and Liu, SX and El-Masry, NA}, year={1999}, month={Nov}, pages={2776–2778} }
 @article{parker_roberts_bedair_reed_liu_el-masry_robins_1999, title={Optical band gap dependence on composition and thickness of InxGa1-xN (0 < x < 0.25) grown on GaN}, volume={75}, ISSN={["1077-3118"]}, DOI={10.1063/1.125079}, abstractNote={Band gap measurements have been carried out in strained and relaxed InxGa1−xN epilayers with x<0.25. Values of x were determined from x-ray diffraction of relaxed films. The lowest energy absorption threshold, measured by transmittance, was found to occur at the same energy as the peak of the photoluminescence spectrum. Bowing parameters for both strained and relaxed films were determined to be 3.42 and 4.11 eV, respectively. The dependence of the band gap shift, ΔEg, on strain is presented.}, number={17}, journal={APPLIED PHYSICS LETTERS}, author={Parker, CA and Roberts, JC and Bedair, SM and Reed, MJ and Liu, SX and El-Masry, NA and Robins, LH}, year={1999}, month={Oct}, pages={2566–2568} }