Abstract

Semiconductors based on tin(ii) show promising hole-transport characteristics due to the 5s electrons that form the valence band. In this paper, we report the synthesis and comprehensive characterization of tin(ii) thiocyanate [Sn(NCS)<inf>2</inf>] and identify it as a novel transparent coordination polymer semiconductor. The single crystal X-ray analysis reveals covalently-bonded 1D polymeric chains that form a 2D structure through Sn-S tetrel bonds. Density functional theory calculations also confirm the importance of the van der Waals interactions between the 2D sheets. Furthermore, we show that the s character of Sn(ii) is maintained at the top of the valence band, resulting in dispersed states with a small hole effective mass. The coordination with NCS ligands also leads to a conduction band which is high in energy, giving rise to a wide band gap and excellent transparency in the visible spectrum. This is the first report on the electronic properties of Sn(NCS)<inf>2</inf> which highlights the potential of developing new transparent semiconductors based on thiocyanate coordination polymers.