Facultatea de Fizică şi Inginerie / Faculty of Physics and Engineering

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Subject: search.filters.subject.Heterojunction

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    Electrical and photoelectrical properties of heterojunctions on the base of Cu(InGa)Se2 [Articol]
    (2005) Chetruș, Petru; Gașin, Petru; Nicorici, Valentina; Suman, Victor
    CdS films deposited by hot wall technique on mica were used as substrates for Cu(InGa)Se2 deposition. Two methods were used for the deposition of Cu(InGa)Se2 films: a) vacuum thermal evaporation from a single source and b) “flash” evaporation. The obtained films were of p-type conductivity with hole concentration varied from 2×1018 cm-3 to 6×1020 cm-3 depending on the fabrication method. The structures Cu(InGa)Se2–CdS were divided into two groups: the structures of type I having the CdS film thickness from 1.6 m to 2.8 m and the structures of type II having the CdS film thickness from 0.6 m to 0.8 m. It was established that the direct/reverse current ratio is 8-16. For the first type heterostructures the diffusion potential is 1.2–1.8 V and for the second type is 0.2–0.34 V. The Cu(InGa)Se2–CdS fotosensitivity is situated in the wavelength region from 0.51 m to 1.1 m and is determined by the electron-hole pair generation in both materials.
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    Optical and photoelectrical properties of GaS and CdTe thin FILMS, components of GaS/CdTe heterojunctions [Articol]
    (2006) Cuculescu, Elmira; Evtodiev, Igor; Caraman, Mihail; Rusu, Mihaela
    In the paper, experimental results concerning the absorption and photosensibility spectral dependence of GaS and CdTe thin film components of GaS/CdTe heterojunctions are presented. GaS films (d = 0.06 μm – 2.8 μm) were deposited onto ITO substrate by laser light pulses. CdTe films (d = 3.6 μm) were deposited onto GaS films by close-spaced sublimation technique. At the fundamental absorption edge, the absorption coefficient of CdTe layers increases of five orders of magnitude in a narrow 40 – 100 meV energy range, up to 4 104cm-1. At room temperature, the energy band of GaS/CdTe heterojunctions photosensitivity is 1.45 eV-2.75 eV, the photocurrent having a constant value up to 2.0 eV photon energy.
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    Effect of heat treatment in presence of CdCl2on the physical properties of pCdTe/nCdS heterojunction solar cells [Articol]
    (CEP USM, 2016) Al Qassem, Amjad
    The article is a comprehensive study of the effect of heat treatment in presence of a cadmium chloride(CdCl2)onthe physical properties of pCdTe/nCdSsolar cells. Heat treatment process plays a key role in enhancing the pCdTe/nCdS hetero- structure photosensitivity, thus improving the performance of solar cells based o n them.This article outlines the changes in the structural characteristics and photoelectric properties of such solar cells before and after heat treatment process. The two most popular methods of the heat treatment process based on cadmium chloride are also discussed.One may consider the CdCl2 heat treatment process as one of the very important stages of preparing CdTe/CdO/CdS solar cells,which improves the performance of these cells made in laboratories of the State University of Moldova.