Design, fabrication, and characterization of a low-power, high-modulation-depth infrared emitter array

The synthesis of flexible zeolite nanofibers by a polymer surface thermal etching process

A study of thermal etching of GaN by atmospheric argon inductively coupled plasma

Surface chemistry of thermal dry etching of cobalt thin films using hexafluoroacetylacetone (hfacH)

We discuss scanning electron micrographs and atomic force microscope images of thermally etched GaAs(1 1 3) surfaces. The GaAs(1 1 3)A and GaAs(1 1 3)B surfaces are compared. The polarity of the surface leads to a different morphology for the two surfaces after thermal etching. It is found that the Ga-enriched droplets, which form under As-deficient conditions at higher temperatures, are sitting on characteristic pedestals, which are different for the two faces. The facets occurring after this thermal etching process are identified. They represent thermally favourable surfaces under the arsenic-deficient conditions of the thermal etching process. © 1998 Chapman & Hall

We report a study of GaN regrowth on micro‐facetted GaN templates formed by in‐situ thermal etching in a low‐pressure metalorganic chemical vapor deposition system. First, the 1.5 µm‐thick GaN epilayers were grown on c‐plane sapphire substrates. This was followed by an in‐situ thermal etching process under hydrogen and ammonia ambient with the etching time being a parameter. The thermally etched GaN templates showed hexagonal GaN pyramids, which were aligned along the growth direction on the c‐plane substrate. The 3 µm‐thick GaN regrowth was performed on these micro‐facetted GaN templates. The surface of the overgrown GaN was atomically smooth. The full width at half maximum of (102) peak in the X‐ray rocking curve profile decreased from 9.5 to 6.5 arcmin as the thermal etching time increased from 0 to 45 min. Etch pit density measurements revealed that the pit density of regrown GaN decreased by about one order of magnitude, compared to that of the control sample. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Influence of PCM design parameters on thermal and optical performance of multi-layer glazed roof

g-C3N4 nanosheets with tunable CO2 adsorption properties and nanostructures were synthesized and incorporated into polyether block amide (Pebax) membrane for CO2 separation. The g-C3N4 nanosheets with variable adsorption properties were produced from two monomers, dicyandiamide and melamine, and the variation of nanostructures was controlled by thermal oxidation etching process. The effects of CO2-philic and molecular sieving properties of g-C3N4 nanosheets on solubility and diffusivity of gas molecules in the as-prepared membranes were systematically investigated. The results demonstrated that the g-C3N4 nanosheets produced from dicyandiamide and undergoing 4 h thermal etching (DCN-4 nanosheets) showed the optimal CO2 sorption and sieving property. The membrane with 0.25 wt% DCN-4 nanosheets exhibited simultaneous enhancement in CO2 permeance and CO2/N2 selectivity compared with pure Pebax membrane. Moreover, the membrane maintained its separation performance during long-term operation test, showing great potential for CO2 capture.

g-C3N4 nanosheets with tunable affinity and sieving effect endowing polymeric membranes with enhanced CO2 capture property

In this study, we propose a centrifugation packaging (CP) structure to enhance the optical and thermal dissipation performance of LEDs, using SBA-15 particles to facilitate the sedimentation and dispersion of QDs. The results indicate that the EL spectra of the LEDs remains almost unchanged after the centrifugation time of 60 min and a CP structure can be obtained. The radiation power and luminous flux of LEDs with a CP structure improve by 9.1% and 10.4%, respectively, compared with the uniform distribution (UD) structure. The surface temperature of LED devices with the CP structure is reduced to 34.4 °C from 41.8 °C at a current of 100 mA. Furthermore, the simulation results show that the maximum temperature in the CP structure is 22.4% lower than that in the UD structure at a current of 500 mA. Thus, this study can provide a new perspective for designing settlement structures of QD-LEDs to enhance their optical and thermal performance.

Two hybridized skeleton borates [Zn(en)2]·[B7O12(OH)] (1; en = ethylenediamine) and [Cd(1,3-dap)2]·[B5O8(OH)]·H2O (2; 1,3-dap = 1,3-diaminopropane) were solvothermally synthesized. The boron oxide clusters formed 2D planes, and these planes formed a 3D structure through co-oxygen links of metal complexes. Herein, a novel strategy has been developed, i.e., the derived guest carbon materials from semi-decomposed borate are incorporated into the void of host borate crystals in situ during the thermal etching process. Moreover, the effect of temperature on fluorescence of derived carbon materials was studied. By controlling the calcining temperature, carbon dots with obvious free radicals can be found via ESR technique. Carbon dots in the ethanol phase exhibited variable photoluminescence. Furthermore, it derived semi-decomposition carbon materials via thermal etching based on compounds 1 and 2. In an hydrogen cell reactor, carbon material Zn-based catalyst 1-200 catalyzes CO2 reduction to CO with a selectivity that reaches 50.8% at -1.4 V vs RHE.

The objective of this work is the integration of a linear cavity receiver in an asymmetric compound parabolic collector. Two different numerical models were developed; one for the conventional geometry and one for the cavity configuration. Both models were examined for inlet temperatures from 20 °C up to 80 °C, considering water as the operating fluid with a typical volume flow rate of 15 lt/h. Emphasis was given to the comparison of the thermal and optical performance between the designs, as well as in the temperature levels of the fluids and the receiver. The geometry of the integrated cavity receiver was optimized according to two independent parameters and two possible optimum designs were finally revealed. The optimization took place regarding the optical performance of the collector with the cavity receiver. The simulation results indicated that the cavity design leads to enhancements of up to 4.40% and 4.00% in the optical and thermal efficiency respectively, while the minimum possible enhancement was above 2.20%. The mean enhancements in optical and thermal performance were found to be 2.90% and 2.92% respectively. Moreover, an analytical solution was developed for verifying the numerical results and the maximum deviations were found to be less than 5% in all the compared parameters. Especially, in thermal efficiency verification, the maximum deviation took a value of less than 0.5%. The design and the simulations in the present study were conducted with the SolidWorks Flow Simulation tool.

Photo-thermal design and analysis of a novel CPC coupled solar air evacuated tube collector

Defect structures formed on Si(001) surfaces heated to different temperatures were studied comparatively with a high-resolution spot profile analysis low-energy electron diffraction (LEED) system and with a scanning tunnelling microscope. Using scanning tunnelling microscopy (STM) we observed tetragonal pyramids after annealing the surface to 1400 K which are formed by a thermal etching process that removes silicon from the surface. With increasing slope of the pyramid planes we observe a transformation from monatomic to DB double steps. For the latter, dimer rows of the (2*1) reconstruction extend perpendicular to the step edges. Pyramid planes with DB double steps that are rotated by 90 degrees transform into each other by the formation of single-stepped planes. For annealing temperatures of 1600 K, very flat surfaces with only monatomic steps are formed. A profile analysis of the specular and half-order beams of the two-domain Si(001) (2*1) LEED pattern was performed after the same preparation procedures were applied to the samples. This analysis leads to step structures that are identical with the results from the real-space STM studies.

Numerical investigation of thermal and optical performance of window units filled with nanoparticle enhanced PCM

Thickness effects of Ni on the modified boron doped diamond by thermal catalytic etching for non-enzymatic glucose sensing