Electrical Properties of Compact Drop-Casted Cu2SnS3 Films

Abstract

We investigated temperature-dependent electrical conduction of Cu2SnS3 (CTS) thin films in the range of 77-500 K synthesized by drop-casting molecular ink. The films were directly formed by drop-casted molecular ink, consisting of a Cu+2-Sn+2-thiourea complex dissolved in a mixture of ethylene glycol-isopropyl alcohol and annealed. The CTS films have a smooth layer with a compact structure, as revealed by cross-sectional scanning electron microscopy. The films are p-type and show a band gap of 1.18 eV. The electrical conductivity and Hall mobility of the films were found to be 1.1 S/cm and 6.72 cm2 V1 s1 , respectively. Data from temperature-dependent measurements show hopping and thermally activated conduction below and above 300 K, with an activation energy of 10 and 90 meV, respectively. Our results suggest that the drop-casted CTS films can be used as an absorber layer in thin film solar cells at an affordable cost.