Chalcogen-based transparent conductors

Abstract Chalcogenide-oxides and chalcogenide-fluorides exhibit p -type conductivity and transparency, and in many cases, these properties exist simultaneously. We present the properties of several of these materials, BaCuQF (Q = S, Se, Te), BiCuOSe, and Cu 3 TaS 4 . BiCuOSe is a low band gap degenerate semiconductor with a high conductivity, and oriented films can be easily prepared. We show that epitaxial thin films of BaCuTeF and highly c -axis oriented films of BaCuSeF can be prepared by pulsed laser deposition on MgO substrates. Undoped BaCuTeF thin films exhibit a maximum conductivity of 167 S/cm, mobility of 8 cm 2 /Vs and band gap of 3 eV, while the selenide and sulfide versions are progressively less conducting and exhibit lower mobility. Strong excitonic features are observed in BaCuSeF and BaCuSF. Cu 3 TaQ 4 powders and films have been prepared and these show p -type conductivity, with absorption onsets in the range 2.8–3.0 eV.