Solution-processed CdS thin films from a single-source precursor

Abstract

Herein we outline the in situ formation of a solution processable CdS precursor, which undergoes facile thermal decomposition to form thin films of the metal sulfide. Through the use of ¹H and ¹³C nuclear magnetic resonance spectroscopy (NMR) and single crystal X-ray diffraction (XRD) we examine the speciation of [Cd(EtXn)₂] upon dissolution and investigate the decomposition of the xanthate complex with Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis-mass spectroscopy (TGA-MS) and head space gas chromatography mass spectroscopy (HS GC-MS). The effect of using a CdCl₂ treatment to promote crystallite growth at various temperatures is elucidated by thin film XRD, scanning electron microscopy (SEM), ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy. Field effect transistors are fabricated to measure the mobility of the CdS thin films and spectral photoconductivity measurements reveal optimised deposition conditions give thin films with optoelectronic properties comparable to those of CdS formed by chemical bath deposition.