@article{moody_barletta_el-masry_roberts_aumer_leboeuf_bedair_2002, title={Effect of H-2 on nitrogen incorporation in the metalorganic chemical vapor deposition of GaAs1-yNy (0 <= y <= 0.08)}, volume={80}, ISSN={["0003-6951"]}, DOI={10.1063/1.1464225}, abstractNote={The effect of hydrogen on the incorporation of nitrogen in GaAs1−yNy grown by metalorganic chemical vapor deposition (MOCVD) is reported. Nitrogen content as high as y=0.081 has been achieved when the use of H2 is completely avoided in the MOCVD growth of GaAs1−yNy. When H2 is added to the growth ambient, the value of y in GaAs1−yNy decreases as the relative percent of H2 in the carrier gas increases. We will report on the properties of these GaAsN films and discuss the nature of the effect that H2 has on modulating the N content in these films.}, number={14}, journal={APPLIED PHYSICS LETTERS}, author={Moody, BF and Barletta, PT and El-Masry, NA and Roberts, JC and Aumer, ME and LeBoeuf, SF and Bedair, SM}, year={2002}, month={Apr}, pages={2475–2477} }
 @article{aumer_leboeuf_moody_bedair_nam_lin_jiang_2002, title={Effects of tensile, compressive, and zero strain on localized states in AlInGaN/InGaN quantum-well structures}, volume={80}, ISSN={["0003-6951"]}, DOI={10.1063/1.1469219}, abstractNote={The recombination dynamics of optical transitions as well as strain effects in AlInGaN/In0.08Ga0.92N quantum wells (QWs) were studied. QW emission energy, photoluminescence decay behavior, photoluminescence emission line shape, and nonradiative recombination behavior were found to be strong functions of strain as well as localization. The degree of carrier localization was inferred by modeling several aspects of optical behavior obtained from variable temperature time-resolved photoluminescence experiments. According to the modeling results, the degree of localization was found to be a minimum for unstrained QWs and increased as either tensile or compressive strain increased, indicating that InGaN QW microstructure is a function of the lattice-mismatch-induced strain experienced during deposition.}, number={17}, journal={APPLIED PHYSICS LETTERS}, author={Aumer, ME and LeBoeuf, SF and Moody, BF and Bedair, SM and Nam, K and Lin, JY and Jiang, HX}, year={2002}, month={Apr}, pages={3099–3101} }
 @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{el-masry_behbehani_leboeuf_aumer_roberts_bedair_2001, title={Self-assembled AlInGaN quaternary superlattice structures}, volume={79}, ISSN={["0003-6951"]}, DOI={10.1063/1.1400763}, abstractNote={When an AlInGaN quaternary alloy is grown by metalorganic chemical-vapor deposition under certain growth conditions, a self-assembled superlattice structure is obtained. The superlattice structure is made of quaternary layers with different AIN and InN compositions. Transmission electron microscopy data show that the superlattice periodicity is regular with an individual layer thickness that depends on the growth conditions. Secondary ion mass spectrometry measurements show that the layers’ composition alternate between high-AIN and InN content and low-AlN and-InN content, while the in-plane lattice constant remains constant for both layers. A model is presented as a preliminary effort to explain these results.}, number={11}, journal={APPLIED PHYSICS LETTERS}, author={El-Masry, NA and Behbehani, MK and LeBoeuf, SF and Aumer, ME and Roberts, JC and Bedair, SM}, year={2001}, month={Sep}, pages={1616–1618} }
 @article{aumer_leboeuf_moody_bedair_2001, title={Strain-induced piezoelectric field effects on light emission energy and intensity from AlInGaN/InGaN quantum wells}, volume={79}, ISSN={["1077-3118"]}, DOI={10.1063/1.1418453}, abstractNote={We report on the effects of the piezoelectric field and well width on the transition energy and intensity for InGaN quantum well structures with GaN or AlInGaN quaternary barriers. It was found that the emission energy of compressively strained GaN/In0.08Ga0.92N quantum wells exhibits a strong well width dependence not accounted for by quantum confinement subband energy shifting alone. However, for unstrained quantum well layers with quaternary barriers, no emission energy dependence on width was observed due to the elimination of the piezoelectric field, which was measured to be at least 0.6 MV/cm for the strained quantum wells. Furthermore, the unstrained quantum wells demonstrated a higher intensity than their strained counterparts for all quantum well widths investigated. The current data will help clarify the origin of emission in InGaN quantum wells.}, number={23}, journal={APPLIED PHYSICS LETTERS}, author={Aumer, ME and LeBoeuf, SF and Moody, BF and Bedair, SM}, year={2001}, month={Dec}, pages={3803–3805} }
 @article{aumer_leboeuf_bedair_smith_lin_jiang_2000, title={Effects of tensile and compressive strain on the luminescence properties of AlInGaN/InGaN quantum well structures}, volume={77}, ISSN={["0003-6951"]}, DOI={10.1063/1.1306648}, abstractNote={We report on the luminescence properties of AlInGaN/In0.08Ga0.92N quantum wells (QWs) subjected to a variable amount of lattice mismatch induced strain, including wells with zero strain, compressive strain, and tensile strain. The primary peak emission energy of a 3 nm In0.08Ga0.92N QW was redshifted by 236 meV as the stress in the well was changed from −0.86% (compressive) to 0.25% (tensile). It was also found that the photoluminescence intensity of quantum wells decreased with increasing strain. A lattice matched 9 nm QW exhibited a luminescence intensity that is three times greater than its highly strained counterpart. The potential applications of this strain engineering will be discussed.}, number={6}, journal={APPLIED PHYSICS LETTERS}, author={Aumer, ME and LeBoeuf, SF and Bedair, SM and Smith, M and Lin, JY and Jiang, HX}, year={2000}, month={Aug}, pages={821–823} }
 @article{leboeuf_aumer_bedair_2000, title={Exploring the effects of tensile and compressive strain on two-dimensional electron gas properties within InGaN quantum wells}, volume={77}, ISSN={["0003-6951"]}, DOI={10.1063/1.126889}, abstractNote={With the advent of high-quality AllnGaN quaternary cladding, InGaN quantum wells (QWs) have now been studied under both compressive and tensile strain, as well as no strain at all! This has allowed the experimental investigation of the two-dimensional electron gas (2DEG) properties within InGaN QWs that have been subjected to a full range of strain, opening the doors to a new realm of strain engineering. We present the capacitance–voltage-derived 2DEG properties of several In0.08Ga0.92N QWs subject to various degrees of strain. Strained In0.08Ga0.92N QWs clad with GaN exhibit better 2DEG confinement than their unstrained Al0.24In0.09Ga0.67N-clad counterparts. For the case of compressive-strained QWs, it was found that the peak 2DEG concentration increases linearly with well width. In contrast, such dependence was not observed for the case of unstrained QWs with lattice-matched cladding. Of further interest, the 2DEGs for compressive and tensile In0.08Ga0.92N QWs are localized at opposite interfaces, which is attributed to strain-induced piezoelectric fields pointing in opposite directions.}, number={1}, journal={APPLIED PHYSICS LETTERS}, author={LeBoeuf, SF and Aumer, ME and Bedair, SM}, year={2000}, month={Jul}, pages={97–99} }
 @article{aumer_leboeuf_mcintosh_bedair_1999, title={High optical quality AlInGaN by metalorganic chemical vapor deposition}, volume={75}, ISSN={["0003-6951"]}, DOI={10.1063/1.125336}, abstractNote={We report on the metalorganic chemical vapor deposition of the quaternary alloy AlInGaN. We found it desirable to grow quaternary films at temperatures greater than 855 °C in order to suppress deep level emissions in the room-temperature photoluminescence. Details of the conditions necessary to grow In0.1Ga0.9N at 875 °C are presented. Strained and relaxed AlInGaN films were grown with good optical and structural properties for AlN compositions up to 26% and InN content up to 11%. The effects of strain were observed by a difference in the band gap between thin and thick films with the same compositions. The potential impact of the use of quaternary films is discussed regarding strain engineering for the improvement of present device designs.}, number={21}, journal={APPLIED PHYSICS LETTERS}, author={Aumer, ME and LeBoeuf, SF and McIntosh, FG and Bedair, SM}, year={1999}, month={Nov}, pages={3315–3317} }
 @article{mcintosh_piner_roberts_behbehani_aumer_elmasry_bedair_1997, title={Epitaxial deposition of GaInN and InN using the rotating susceptor ALE system}, volume={112}, ISSN={["0169-4332"]}, DOI={10.1016/S0169-4332(96)00992-0}, abstractNote={The growth of GaInN ternary alloys has been investigated using atomic layer epitaxy. Single crystal films have been deposited at 100 Torr in the 600°C to 700°C temperature range using the rotating susceptor approach. The InN percentage in the deposited films were found to depend on more than just the gas phase In/Ga ratio. In addition to the relative indium to gallium composition of the precursor gases, the indium incorporation was also found to depend on the absolute partial pressures of the reactant gases. The indium incorporation increases with decreasing growth temperatures, and may reach a temperature dependent saturation limit for a given set of growth conditions. Optimization of the ALE growth process has resulted in single crystal films exhibiting band edge room temperature photoluminescence for InN percentages of up to 27% in the GaInN ternary films. In addition, single crystal indium nitride has been grown using the ALE technique at 480°C.}, journal={APPLIED SURFACE SCIENCE}, author={McIntosh, FG and Piner, EL and Roberts, JC and Behbehani, MK and Aumer, ME and ElMasry, NA and Bedair, SM}, year={1997}, month={Mar}, pages={98–101} }