Synthesis and Characterization of Cu₃(Sb_1–<i>x</i>As_<i>x</i>)S₄ Semiconducting Nanocrystal Alloys with Tunable Properties for Optoelectronic Device Applications

Abstract

A synthetic method for producing monodisperse Cu3(Sb1–xAsx)S4 nanocrystals (NCs) with highly tunable semiconducting properties is discussed. Additionally, significant improvement in collectible photocurrent is observed for arsenic-rich compositions, with a 10-fold improvement in photocurrent density from Cu3AsS4 NC thin films compared to the more well-studied Cu3SbS4 composition. Interestingly, this improvement in photocurrent is observed despite the increased optical band gap of the arsenic-rich compositions. These results suggest Cu3AsS4 and arsenic-rich compositions of Cu3(Sb1–xAsx)S4 may yield higher photocurrent densities for solar conversion devices. Furthermore, the simple and robust synthesis, scalable spray coating strategy, and highly tunable nature of the NCs provides a foundation encompassing numerous fields requiring inexpensive and earth-abundant semiconducting materials.