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Highlights: [•] Highly photosensitive n-CuIn5Se8 photoabsorber layers were prepared by PVD. [•] The structures annealed in vacuum show dominating presence of the CuIn5Se8 phase. [•] Annealing in argon and vacuum in sequence gives the best morphology. [•] CuIn5Se8 layers annealed at 500°C for 2h in vacuum show maximal photosensitivity. [•] Prepared photoabsorber layers can be potentially applied for hybrid solar cells. [ABSTRACT FROM AUTHOR]

Abstract: Different sequentially stacked binary chalcogenide layers (CuSe, ZnSe, and SnSe) deposited by vacuum evaporation onto molybdenum covered soda-lime glass substrates were used as precursors to form Cu2ZnSnSe4 films. The influence of the stacked binary layer sequence, substrate temperature, both the duration and speed of deposition and the post deposition treatment atmosphere on the structural and the morphological parameters of the Cu2ZnSnSe4 thin films was studied. Our results indicate the possibility of replacing the Se2 selenisation with a thermal treatment in an SnSe2 atmosphere to avoid the selenisation of the Mo substrate and MoSe2 formation. This SnSe2 treatment forms p-type Cu2ZnSnSe4 films with an optical band-gap of 1.14eV and a solar cell structure with an efficiency of up to 3%. [Copyright &y& Elsevier]

Abstract: Two types of superstrate glass/ITO/CdS/CdTe PV structures were prepared by high vacuum evaporation technique with (i) activation of CdS layer and CdS/CdTe bi-layer structure step-by-step and (ii) activation of CdS/CdTe bi-layer structure. The activation was performed by annealing the structures with CdCl2 in air at 400°C for 15min. Main conditions for CdS and CdTe thin films deposition and following treatment were selected from the literature data with the purpose to prepare and compare complete CdTe solar cells with standard p+Cu x Te back contact and conductive polymer poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonic acid (PEDOT:PSS) back contact. Obtained layers and structures were characterized using the XRD, SEM and I-V methods. Both the methods of activation treatment give comparable results from the point of view PV properties of complete solar cells. It was found that highly conductive PEDOT:PSS intermediate layer can significantly improve the back contact characteristics of CdTe. However these hybrid structures need to be further optimized to compete successfully with conventional inorganic back contacts in complete CdTe solar cells. [Copyright &y& Elsevier]

Abstract: Thin films of CuIn3Se5 photoabsorber were deposited from the stoichiometric polycrystalline precursor onto glass/ITO substrates by using the high vacuum evaporation technique and following annealing in argon. The chalcopyrite structure of obtained films of CuIn3Se5 were confirmed by the XRD spectroscopy. The SEM micrographs, Raman spectra and EDS data confirm the enhanced morphology and composition of prepared CuIn3Se5 films. The obtained glass/ITO/CuIn3Se5/graphite sandwich structures demonstrate diode-shape I-V characteristics and photosensitivity. The annealed CuIn3Se5 films have a p-type of conductivity with the free carriers’ concentration in the range of 1016–1017 cm−3. An electrical equivalent circuit consisting of constant phase elements was used for modeling of the impedance spectroscopy measurements. Both impedance modeling and capacitance-voltage () curves show that there is a strong minority carrier accumulation process taking place at forward potentials. [ABSTRACT FROM AUTHOR]

Abstract: As an answer to the increasing energy demand of mobile battery-powered electronic devices, we propose a new approach offering an autonomous power source. Comprising a thin film organic or hybrid solar cell connected to a Lithium-polymer (Li-polymer) battery, the so-called EURO-PSB device possesses attractive characteristics like low weight (<10g), small thickness (<1mm) and mechanical flexibility. Thanks to a smart interconnection between the two units, the battery is always charged with optimized voltage, independent of the illumination conditions. Such a product, compatible with roll-to-roll production processes, might open a new way for producing and storing energy for small consumption electronic devices. [Copyright &y& Elsevier]

Abstract: This study demonstrates that the combined method for the formation of thin composite films, consisting of polypyrrole (PPy) as a film forming agent and polyparaphenylene (PPP) with controlled electrical properties and high stability, enables one to avoid the low processability of PPP and to extend the possibilities for the development of electronic devices. The high temperature (250–600 °C) doping method was used for PPP preparation. The crystallinity and grindability of PPP was found to be increasing with the thermochemical modification. Thin composite films were prepared onto the light transparent substrates using the simple electropolymerization technique. The properties of films were characterized by the optical transmittance and temperature-dependent conductivity measurements. The morphology and thickness of the prepared films were determined using the scanning electron microscopy. The composite films showed a better adhesion to an inorganic substrate. It was found to be connected mostly with the improved properties of the high temperature doped PPP. The current–voltage characteristics of indium tin oxide/film/Au hybrid organic–inorganic structures showed the influence of the doping conditions of PPP inclusions in the obtained films. [Copyright &y& Elsevier]

Abstract: Hybrid PV structures based on polycrystalline photoabsorber Cu–In–Se (CISe) and electrically conductive polymer polypyrrole (PPy) were prepared using the electrodeposition technique. The PPy is considered as p-type barrier layer on n-CISe in the cell structure. Photoactive CISe thin films of various compositions were deposited electrochemically onto glass/ITO substrates from aqueous solutions containing CuSO4, In2(SO4)3 and SeO2. All the obtained polycrystalline CISe films were annealed in vacuum to improve the crystalline structure and etched in 10% KCN to remove the additional phases. In order to prepare the PV structures, thin PPy films doped with β-naphthalene sodium sulfonate were galvanostatically electrodeposited onto the CISe films. Appropriate parameters of electrodeposition were selected experimentally. The morphology and thickness of the prepared film layers were determined using the SEM technique. The chemical composition of the CISe films was determined by energy dispersive X-ray spectroscopy (EDS). To investigate the electrical properties of the obtained structures, current–voltage and impedance characteristics were measured. The best structure showed an open-circuit voltage of 138 mV and a short-circuit current density of 2.55 mA/cm2 under white light illumination with an intensity of 100 mW/cm2. [Copyright &y& Elsevier]

Abstract: The mechanism of the underpotential electrodeposition of copper indium diselenide (CIS) in the presence of an excess of In3+ was studied. It was found that the value of indium and copper ratio (In/Cu) in the films electrodeposited in the potentials area from −0.2 to −0.6 V (vs. SCE) is independent of the concentration ratio of Cu2+/In3+. At the same time, the concentration of indium in the films obtained is determined both by the deposition potential and the ratio of Se(IV)/Cu2+ in the solution. The proposed model provides the list of the formed compounds as a function of the solution concentration and the applied potential. [Copyright &y& Elsevier]

Abstract: Photovoltaic (PV) structures based on inorganic photoabsorber CuInS2 (CIS) in combination with conductive polymers polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT) were prepared using electrodeposition and spin-casting techniques. The conductive polymer layer is considered as the p-type buffer layer and window layer on CIS absorber layer in the cell structure. The CIS thin films were fabricated using a non-vacuum CISCuT technique on Cu tape substrate. All obtained polycrystalline CIS films were etched in 10% KCN and annealed in vacuum to improve the crystalline structure. PPy films doped with β-naphthalene sodium sulfonate were electrodeposited under white light illumination onto the pretreated CIS films. Thin PEDOT films doped with polystyrenesulfonate (PSS) were deposited onto the CIS films from an aqueous dispersion of PEDOT/PSS mixed with N-methylpyrrolidone, isopropanol, glycerin and epoxysilane additives using the spin-casting technique. In order to prepare stable PPy and PEDOT films with a good adherence to the surface of inorganic semiconductor CIS, the appropriate parameters of electrodeposition and spin-coating were selected experimentally. Significant photovoltage and photocurrent of the fabricated complete structures have been observed under standard white light illumination. [Copyright &y& Elsevier]

Abstract: This paper deals with the formation of Cu2ZnSnSe4 (CZTS) in the process of selenization of metal precursor layers in elemental selenium vapour. Metallic precursors were sequentially evaported from Sn, Zn and Cu sources. Precursor Sn–Zn–Cu films have a “mesa-like” structure and consist mainly of Cu5Zn8 and Cu6Sn5 phases. It was confirmed that the formation of different binary copper selenides is the dominating process of selenization in elemental Se vapour at temperatures up to 300°C. The formation of kesterite CZTS films begins at 300°C and dominates at higher temperatures, always resulting in multiphase films that consist of high-quality Cu2ZnSnSe4 crystals and of a separate phase of ZnSe. [Copyright &y& Elsevier]

Abstract: The paper summarizes the results of R/D in new alternative materials and in thin film and monograin solar cells at EU Centre of Excellence in PV Materials and Devices at TUT. The defect structure of various chalcopyrite compounds (CuInSe2, CuInS2, CuGaSe2, CuGaTe2, AgGaTe2, CuInTe2, AgInTe2, Cu2ZnSnSe4) was studied. A novel route of spray deposition was developed to prepare ZnO layers comprising nanorods as a promising material for solar cells. Technological conditions for controlled ZnS chemical bath deposition were determined. The influence of parameters of electrodeposition and annealings in different atmosphere to the composition and morphology of CuInSe2 thin films was studied. Hybrid solar cells on the basis of CuInS2 and CdTe photoabsorbers in combination with organic functional layers were prepared and investigated. All the obtained results were used to optimize the technology of producing solar cell structures in different designs. [Copyright &y& Elsevier]

Abstract: CuInSe2 (CIS) films have been prepared by one-step electrodeposition technique. The effect of thermal treatment in vacuum and under selenium vapour pressure on the composition and structure of CIS electrodeposited layers has been investigated. The structure and composition of these samples have been investigated by SEM, XRD, EDX and Raman spectroscopy. It was found that recrystallization of CIS thin film occurs with segregation of Cu–Se phases onto the bottom of films and formation of CIS grains different by size and composition. [Copyright &y& Elsevier]

Abstract: Cu–In–Ga (CIG) layers of graded composition have been grown by one-step electrodeposition from thiocyanate complex electrolytes. The Ga-content is adjusted from two to 30 at.% by changing stirring rate, deposition time and solution composition. The as prepared CIG precursors are selenizated at 500 °C in a two-temperature zone furnace at different Se-vapour pressures. The influence of the Se-vapour pressure on morphology and photoluminescence properties of Cu(In, Ga)Se2 films are discussed. [Copyright &y& Elsevier]