Građa i optička svojstva tankih polikristaliničnih slojeva CuGaxIn1−xSe2

Structural and optical properties of CuGaxIn1−xSe2 (0 ≤ x ≤ 0.75) polycrystalline thin films deposited by vacuum evaporation were studied as a function of composition. The optical absorption spectra of CuGaxIn1−xSe2 thin films (x /=0) show four energy gaps (Eg1 , Eg2 , Eg3 and Eg4 ) which are attributed to the fundamental edge, band splitting by crystal-field and spin-orbit splitting, and to transitions originating from copper 3d levels, respectively. The primary transition energies exhibit bowing behaviour expressed by the relationship Eg1 (x) = 1.011 + 0.448x + 0.186x 2 . The second and third transition energies are higher than the primary transition energies by 0.10–0.11 eV and 0.18–0.185 eV, respectively. The effect of thermal treatment on the values of energy gaps is discussed in terms of the structure of the films. The primary transition energies of annealed CuGaxIn1−xSe2 can be fitted by the parabolic form Eg1 (x) = 1.04 + 0.46x + 0.22x 2 .Proučavali smo strukturna i optička svojstva tankih polikristaliničnih slojeva CuGaxIn1−xSe2, isparenih u vakuumu, u ovisnosti o sastavu (0 ≤ x ≤ 0.75). Optički apsorpcijski spektri tankih slojeva CuGaxIn1−xSe2, (x /=0), pokazuju četiri energijska procijepa (Eg1 , Eg2 , Eg3 i Eg4 ) koji se pridjeljuju osnovnom rubu, cijepanju vrpci kristalnim poljem i cijepanju spin-staza, odnosno prijelazima iz 3d stanja bakra. Prvotni prijelazi pokazuju kvadratnu ovisnost koju izražavamo relacijom Eg1 (x) = 1.011 + 0.448x + 0.186x 2 . Druga i treća prijelazna energija su (0.10 − 0.11 eV) odnosno (0.18 − 0.185 eV) više od primarne prijelazne energije. Pomoću građe slojeva objašnjavamo učinak toplinske obrade na vrijednosti energijskih procijepa. Prvotne prijelazne energije opuštenog CuGaxIn1−xSe2 mogu se predstaviti kvadratnim izrazom Eg1 (x) = 1.04 + 0.46x + 0.22x 2

Građa i optička svojstva tankih polikristaliničnih slojeva CuGaxIn1−xSe2

Structural and optical properties of CuGaxIn1−xSe2 (0 ≤ x ≤ 0.75) polycrystalline thin films deposited by vacuum evaporation were studied as a function of composition. The optical absorption spectra of CuGaxIn1−xSe2 thin films (x /=0) show four energy gaps (Eg1 , Eg2 , Eg3 and Eg4 ) which are attributed to the fundamental edge, band splitting by crystal-field and spin-orbit splitting, and to transitions originating from copper 3d levels, respectively. The primary transition energies exhibit bowing behaviour expressed by the relationship Eg1 (x) = 1.011 + 0.448x + 0.186x 2 . The second and third transition energies are higher than the primary transition energies by 0.10–0.11 eV and 0.18–0.185 eV, respectively. The effect of thermal treatment on the values of energy gaps is discussed in terms of the structure of the films. The primary transition energies of annealed CuGaxIn1−xSe2 can be fitted by the parabolic form Eg1 (x) = 1.04 + 0.46x + 0.22x 2 .Proučavali smo strukturna i optička svojstva tankih polikristaliničnih slojeva CuGaxIn1−xSe2, isparenih u vakuumu, u ovisnosti o sastavu (0 ≤ x ≤ 0.75). Optički apsorpcijski spektri tankih slojeva CuGaxIn1−xSe2, (x /=0), pokazuju četiri energijska procijepa (Eg1 , Eg2 , Eg3 i Eg4 ) koji se pridjeljuju osnovnom rubu, cijepanju vrpci kristalnim poljem i cijepanju spin-staza, odnosno prijelazima iz 3d stanja bakra. Prvotni prijelazi pokazuju kvadratnu ovisnost koju izražavamo relacijom Eg1 (x) = 1.011 + 0.448x + 0.186x 2 . Druga i treća prijelazna energija su (0.10 − 0.11 eV) odnosno (0.18 − 0.185 eV) više od primarne prijelazne energije. Pomoću građe slojeva objašnjavamo učinak toplinske obrade na vrijednosti energijskih procijepa. Prvotne prijelazne energije opuštenog CuGaxIn1−xSe2 mogu se predstaviti kvadratnim izrazom Eg1 (x) = 1.04 + 0.46x + 0.22x 2

Influence of Film Thickness and Heat Treatment on the Physical Properties of Mn Doped Sb2Se3 Nanocrystalline Thin Films

Nanocrystalline thin films of Sb37.07Mn1.95Se60.98 with different thickness (7, 20, 40, and 80 nm) were successfully prepared via inert gas condensation technique. As-deposited films showed amorphous structure by grazing incident in-plane X-ray diffraction (GIIXD) technique. All films of different thicknesses were heat treated at 433 K for 90 min. The GIIXD pattern of annealed films showed nanocrystalline orthorhombic structure. The effect of thickness of annealed films on the structure and optical properties was studied. Calculated particle sizes are 20.67 and 24.15 for 40 and 80 nm thickness of heat treated film. High resolution transmission electron microscope HRTEM images and their diffraction patterns proved that 40 nm film thickness annealed at different temperature has nanocrystalline nature with observed (high) crystallinity that increases with annealing temperature. Blue shift of optical energy gap was observed from 1.68 to 2 eV with decreasing film thickness from 80 to 7 nm. Film thickness of 40 nm was exposed to different heat treated temperatures from 353 to 473 K to detect its effect on structure and optical and electrical properties. Blue shift from 1.73 to 1.9 eV was observed in its optical band gap due to direct transition as heat treatment temperature decreasing from 473 to 353 K. Electrical conductivity was studied for different heat treated films of thickness 40 nm, and intrinsic conduction mechanism is dominant. The activation energy Ea was affected by heat treatment process

Characterization of 2-(2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-ylimino)-2-(4-nitrophenyl)acetonitrile and ZnO nano-crystallite structure thin films for application in solar cells

Hybrid (organic/inorganic) heterojunction device based on nano-crystallite structures of 2-(2, 3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-ylimino)-2-(4-nitrophenyl)acetonitrile (DOPNA) and ZnO thin films has been fabricated. The ZnO powder is prepared by the hydrolysis of zinc chloride in the presence of triethanolamine, the ZnO film is prepared by using spin coating technique, whereas the DOPNA thin film is deposited from the powder by the thermal evaporation technique. The formed nano-crystallite structures and lattice parameters of DOPNA and ZnO films have been determined. The optical absorbance of DOPNA and ZnO films are measured and the types of transitions as well as the optical band gap of the films are evaluated. The current-voltage characteristics of ITO/ZnO/DOPNA/Au heterojunction diode in dark and under illumination conditions have been investigated. The capacitance-voltage characteristic showed that the formed junction is of abrupt nature and the built-in potential is estimated. The solar cell parameters have been determined as 0.37 V for open circuit voltage, 1.04 mA for short circuit current, 0.43 for fill factor and 1.56% for power conversion efficiency

Safety of hospital discharge before return of bowel function after elective colorectal surgery

Background Ileus is common after colorectal surgery and is associated with an increased risk of postoperative complications. Identifying features of normal bowel recovery and the appropriateness for hospital discharge is challenging. This study explored the safety of hospital discharge before the return of bowel function. Methods A prospective, multicentre cohort study was undertaken across an international collaborative network. Adult patients undergoing elective colorectal resection between January and April 2018 were included. The main outcome of interest was readmission to hospital within 30 days of surgery. The impact of discharge timing according to the return of bowel function was explored using multivariable regression analysis. Other outcomes were postoperative complications within 30 days of surgery, measured using the Clavien-Dindo classification system. Results A total of 3288 patients were included in the analysis, of whom 301 (9 center dot 2 per cent) were discharged before the return of bowel function. The median duration of hospital stay for patients discharged before and after return of bowel function was 5 (i.q.r. 4-7) and 7 (6-8) days respectively (P < 0 center dot 001). There were no significant differences in rates of readmission between these groups (6 center dot 6 versus 8 center dot 0 per cent; P = 0 center dot 499), and this remained the case after multivariable adjustment for baseline differences (odds ratio 0 center dot 90, 95 per cent c.i. 0 center dot 55 to 1 center dot 46; P = 0 center dot 659). Rates of postoperative complications were also similar in those discharged before versus after return of bowel function (minor: 34 center dot 7 versus 39 center dot 5 per cent; major 3 center dot 3 versus 3 center dot 4 per cent; P = 0 center dot 110). Conclusion Discharge before return of bowel function after elective colorectal surgery appears to be safe in appropriately selected patients