Colloidal Synthesis, Optical Properties, and Hole Transport Layer Applications of Cu2BaSnS4 (CBTS) Nanocrystals

Cu2BaSnS4 (CBTS) is an emerging earth abundant and environmentally benign semiconductor. But there is no prior report of colloidal CBTS nanocrystals. Here we developed a colloidal synthesis of CBTS nanocrystals by rational design. Photophysical properties of these nanocrystals are elucidated using photoluminescence and ultrafast transient absorption spectroscopy. Finally, thin films of CBTS nanocrystals grown at room temperature is used as hole transport layer (HTL) in organic photodiode yielding a high peak specific detectivity (>3.2 × 1012 Jones) with low noise equivalent power (9.20 × 10-14 W Hz0.5). These results suggest that our colloidal CBTS nanocrystals have potentials for optoelectronic applications.