Functional Materials

Structure and optical properties of CdS polycrystalline layers for solar cells based on CdS/CdTe

2019-06-20T22:30:07Z

Structure and optical properties of CdS polycrystalline layers for solar cells based on CdS/CdTe Khrypunov, G.S.; Kopach, G.I.; Dobrozhan, A.I.; Mygushchenko, R.P.; Kropachek, O.V.; Lyubov, V.M. Thin CdS films about 200-500 nm thick with stable hexagonal modification with 85-80 % transparency value respectively in the visible and infrared spectrum regions were investigated. The use of the FTO sublayer to obtain heterosystem glass/FTO/CdS by magnetron sputtering does not affect the phase composition of the cadmium sulfide layer and the width of the band gap (Eg = 2.42-2.44 eV). Cadmium sulfide thin films, obtained by direct current magnetron sputtering, can be used as a layer of a wide window layer in thin-film solar cells based on the CdS/CdTe heterosystem.

Properties of MnO doped graphene synthesized by co-precipitation method

2019-06-20T22:29:48Z

Properties of MnO doped graphene synthesized by co-precipitation method Ilman Nur Sasongko, M.; Poppy Puspitasari; Sukarni; Cepi Yazirin MnO doped graphene specimens were synthesized using a simple and cost-effective method, i.e. co-precipitation. The characterization of specimens was done through various techniques, such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared (FTIR). Single phase pattern on [222], crystallite size, and d-spacing were confirmed by XRD results. The nanostructure morphology was observed using SEM. FTIR showed the shifted peaks and changes in the intensity of molecular bonds of the material. The specimens were sintered for 1 h at various temperatures of 500 °C, 600 °C, and 700 °C. The XRD characterization showed that sintering at 700 °C resulted in MnO and GO peaks with the highest intensity, but the specimen sintered at 600 °C had the best grain size of 70.39 nm. The morphology characterization by SEM showed a change of shape from triangle to nanosphere with agglomeration. The results of FTIR showed that the shifts in C-O and Mn-O groups were followed by an increase in N-H, C-H, C=O, C-O, and Mn-O. The results of this study suggest that single-phase MnO doped graphene was successfully synthesized using the co-precipitation method.

Method of obtaining an organic polycrystalline scintillator for detecting beta-radionuclide sources in natural waters

2019-06-20T22:29:45Z

Method of obtaining an organic polycrystalline scintillator for detecting beta-radionuclide sources in natural waters Andryushchenko, A.Yu.; Belikov, K.N.; Galunov, N.Z.; Martynenko, E.V.; Lazarev, I.V.; Polupan, Ya.I.; Tarasenko, O.A. The method of producing an organic polycrystalline scintillator with two-stage sorbent filled holes for detecting beta-emitting source of 90Sr in natural water is proposed. That confirms that synthetic hydroxylapatite is the optimal sorbent to solving the problem. For the polycrystalline scintillator of p-terphenyl doped by 1,4-diphenylbutadiene-1,3 which has the holes filled with hydroxylapatite as a sorbent, the efficiency of detecting beta particles of 90Sr isotope sorbed from the water sample reaches 90 %.

Production of submicron Al₂O₃ powders by electrochemical dissolution of aluminum in the presence of nitric acid

2019-06-20T22:29:35Z

Production of submicron Al₂O₃ powders by electrochemical dissolution of aluminum in the presence of nitric acid Balabanov, S.S.; Drobotenko, V.V.; Permin, D.A.; Rostokina, E.Ye.; Boldin, M.S.; Murashev, A.A. A cost-effective and easily scalable method for the synthesis of ultrapure submicron alumina powders with a narrow particle size distribution and high sinterability is proposed. Aqueous solutions of aluminum hydroxide nanoclusters obtained by AC electrochemical dissolution of aluminum metal in the presence of nitric acid were used as a precursor. Hot pressing and vacuum sintering were used to evaluate the possibility of obtaining Al₂O₃ optical ceramics from synthesized powders.