AACVD of Cu2−xS, In2S3 and CuInS2 thin films from [Cu(iBu2PS2)(PPh3)2] and [In(iBu2PS2)3] as single source precursors

Abstract

[In(ⁱBu₂PS₂)₃] and [Cu(ⁱBu₂PS₂)(PPh₃)₂] complexes have been synthesized and used as single source precursors to deposit thin films of cubic In₂S₃ and Cu_2−xS respectively on glass substrates by aerosol-assisted chemical vapor deposition (AACVD) at 350–500 °C. Thin films of CuInS₂ have also been deposited by using 1 : 1 molar ratio of [In(ⁱBu₂PS₂)₃] and [Cu(ⁱBu₂PS₂)(PPh₃)₂]. The deposited thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray diffraction (EDX) techniques. Deposition of films at different temperatures showed significant variation in stoichiometry and microstructure. The CuInS₂ thin films were ultrasonicated in toluene along with dodecanthiol for 3 hours to obtain a suspension of CuInS₂ nanocrystallites with a diameter of ca. 18 ± 2 nm and a band gap of 1.59 eV.