Formation of Cu(In1-xAlx)Se2 by selenising RF magnetron sputtered Cu/Al/In precursor layers

The fabrication of Cu(In1-xAlx)Se2 using a multi-step process is reported. This process consists of depositing layers of Cu/Al/In, using magnetron sputtering, to form a metallic precursor layer, capping the stack with a layer of selenium, and then annealing in selenium vapour to synthesise the compound. The effects of annealing conditions on the chemical and physical properties of the converted layers were investigated. Rapid thermal processing at different temperatures indicated the formation of Cu(In1-xAlx)Se2 but only for annealing temperatures<360?C; a CuInSe2 phase was found to be present in all the layers fabricated. Annealing processes at higher temperatures (530-550?C) in a large tube furnace did succeed in producing Cu(In1-xAlx)Se2 without CIS, but only when a copper capping layer was included on the precursor stack

Investigating synthesis of Cu2ZnSn(Se1-x,Sx)4 for values of 0≤x≤1 by S for Se substitution and direct sulphidisation of metallic precursors

Thin layers of Cu2ZnSn(Se1-x,Sx)4 were produced by selenisation and subsequent sulphur substitution of DC sputter-deposited metallic CZT precursors on soda-lime glass. Values of x=(0, 0.07, 0.12, 0.17, 0.28, 1) were measured by EDS. Samples were characterised optically and analysed using the Kubelka-Munk function, and found to have 0.96eV ≤Eg≤ 1.47eV, varying approximately linearly with x. Samples underwent X-ray diffraction characterisation and substituted samples were found to comprise of multiple phase kesterite material with different levels of S substitution, averaging to the values obtained by EDS. The spectra were found to conform to Vegard's law, as peak location shifted linearly between x=0 and x=1. Binary phases are suspected to exist, because of some unusual behaviour at the location of the (200) peak. Lattice parameters for all phases were calculated and found to vary linearly between (a=b=5.692, c=11.338) for x=0 and (a=b= 5.393, c= 10.863) for x=1, which are in excellent agreement with previously published figures

Characterisation of Thin Films CuIn1-xAlxSe2 Prepared by Selenisation of Magnetron Sputtered Metallic Precursors

Thin films of CuIn1-xAlxSe2 have been produced by the selenisation of magnetron sputtered Cu/In/Al precursor layers using elemental selenium and the chemical and physical properties of the layers have been determined for different conditions of synthesis. For optimum conditions of synthesis it was found possible to produce single phase films with the chalcopyrite structure. These films were pinhole free, had good adhesion and were conformal to the substrate. The films had uniform depth profiles as determined using the MiniSIMS. The layers were highly photoactive, indicating that they have the potential to be used to fabricate thin film photovoltaic solar cell devices

Service innovation in manufacturing firms : evidence from Spain.

The ways in which manufacturing firms come to offer services to customers – servitisation or servicisation – are attracting considerable attention. This paper examines an innovation survey of Spanish firms in order to investigate one aspect of this phenomenon: the introduction of new or improved services by manufacturers. Specifically, the paper analyses the determinants of service innovations in manufacturers and determines whether they differ from those of product or process innovations in these same firms. The study finds that almost 20 percent of the firms in the sample have introduced such services in the recent past and that important differences exist between service and product (goods) innovations, with service innovations being particularly related to human resource development and closer links to customers. This suggests that service innovation by manufacturers has much in common with the innovation patterns detected in service sector firms. Intriguing differences across manufacturing sectors are also noted, with the lowest- and highest-tech sectors reporting more service innovations than the medium-tech sectorsInnovation; Manufacturing; Service; Servitisation;

Investigations of ternary Cu3SbS3 thin films as absorber in photovoltaic devices

Magnetron sputtered Cu-Sb metallic precursors were sulphidised on glass and molybdenum/glass substrates at 6 different temperatures. Two techniques were adopted for the elemental sulphidisation process. Precursors sulphidised using evaporated elemental sulphur were successfully converted into Cu3SbS3 solar absorber layers on molybdenum substrates. The as-sulphidised films exhibited p-type conductivity were produced in the limited response when analysed using a Eu+ electrolyte arrangement to measure the photocurrent. The films exhibited an energy bandgap value of 1.84eV

Annealing studies and electrical properties of SnS-based solar cells

Thin films of SnS (tin sulphide) were thermally evaporated onto glass and CdS/ITO (cadmium sulphide/indium tin oxide) coated glass substrates and then annealed in vacuum with the aim of optimising them for use in photovoltaic solar cell device structures. The chemical and physical properties of the layers were determined using scanning electron microscopy, energy dispersive x-ray analysis, x-ray diffraction, and transmittance versus wavelength measurements. “Superstrate configuration” devices were also made using indium tin oxide as the transparent conductive oxide, thermally evaporated cadmium sulphide as the buffer layer and evaporated copper/indium as the back contact material. Capacitance-voltage data are given for the fabricated devices. Capacitance- voltage, spectral response and I-V data are given for the fabricated devices

Quaternary Cu2ZnSnSe4 thin films for solar cells applications

Polycrystalline thin films of Cu2ZnSnSe4 (CZTSe) were produced by selenisation of Cu(Zn,Sn) magnetron sputtered metallic precursors for solar cell applications. The p-type CZTSe absorber films were found to crystallize in the stannite structure (a = 5.684 Ã… and c = 11.353 Ã…) with an electronic bandgap of 0.9 eV. Solar cells with the structure were fabricated with device efficiencies up to 3.2%

Crystallographic properties and elemental migration in two-stage prepared CuIn1−xAlxSe2 thin films for photovoltaic applications

Two-stage fabrication of CuIn1−xAlxSe2 thin films for photovoltaic absorbers using sputtered Cu–In–Al metallic precursors has been investigated. Precursors containing different relative amounts of Al were selenised and their structural and chemical properties characterised. X-ray diffraction (XRD) analyses revealed that the Al was only incorporated into the chalcopyrite structure for precursor composition ratios x = [Al]/([Al] + [In]) ⩾ 0.38, while chemical analysis of the cross-section indicated partial segregation of Al near the back of the film. Precursor films in the range of compositions that yielded no Al incorporation were then selenised at four different temperatures. Glow discharge optical emission spectroscopy, plasma profiling time-of-flight mass spectrometry and XRD analyses provided an insight into the diffusion processes and reactions taking place during the selenisation stage. The effect of post-selenisation annealing without additional Se was also investigated, and led to partial incorporation of the Al into the CuInSe2 lattice but no rediffusion