Broadening of the transmission range of dielectric/metal multilayer structures by using different metals. (January 2015)

• Record Type: Journal Article
• Authors: Mouchaal, Y.; Louarn, G.; Khelil, A.; Morsli, M.; Stephant, N.; Bou, A.; Abachi, T.; Cattin, L.; Makha, M.; Torchio, P.; Bernède, J.C.
• Is Part Of: Vacuum. Volume 111(2015)
• Page Start: 32
• Page End: 41
• Publication Date: 2015-01
• Subjects: Indium free transparent electrode -- Vacuum deposition -- Transmission -- Multi-layer structures -- Metal bilayer; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2014.09.013
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: ZnS/M12 /ZnS structures, with M12 = Ag, Cu or Cu/Ag, were deposited under vacuum by simple joule heating effect (sublimation or evaporation). The optimum thicknesses of the different layers were experimentally determined: 50/45 nm for ZnS, 11 nm for Ag, 16 nm for Cu and 3 nm/9 nm for Cu/Ag. The presence of the double metal Cu/Ag interlayer induces a significant broadening of the optical transmittance spectrum of these structures. The properties of the structures depend strongly on deposition rate of the different films. When the deposition rates of ZnS, Cu are 0.15 nm/s and 0.30 nm/s for Ag, the averaged transmission, between 400 nm and 1000 nm is 85% while the sheet resistance is 5.0 ± 0.2 Ω/sq. These performances allow achieving an averaged factor of merit Φ M, between 400 nm and 700 nm, of 70 × 10 −3 Ω −1 . This averaged value tends toward those usually achieved by transparent conductive oxides. Highlights: ZnS/Cu/Ag/ZnS structure as transparent conductive electrode ITO free. The introduction of a second metal layer induces a broadening of the transmission range. The averaged value of the transmittance between 400 and 100 nm is 84%. The surface roughness depends on the deposition rate of ZnS. RMS value of 1.56 nm can be achieved, when ZnS is deposited at a rate <1.5 A/s.