title: Synthesis of compositionally controllable Cu2(Sn1-xGex)S3nanocrystals with tunable band gaps.
abstract: In this work, we show that compositionally controlled Cu2(Sn1-xGex)S3nanocrystals can be successfully synthesized by the hot-injection method through careful tuning the Ge/(Sn+Ge) precursor ratio. The band gaps of the resultant nanocrystals are demonstrated to be linearly tuned from 1.45 to 2.33 eV by adjusting the composition parameter x of the Ge/(Sn+Ge) ratio from 0.0 to 1.0. The crystalline structures of the resultant NCs have been studied by the X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), select area electron diffraction (SAED), and Raman spectroscopy. A ligand exchange procedure is further performed to replace the native ligands on the surface of the NCs with sulfur ions. The photoresponsive behavior indicates the potential use of as-prepared Cu2(Sn1-xGex)S3nanocrystals in solar energy conversion systems. The synthesis of compositionally controlled Cu2(Sn1-xGex)S3nanocrystals reported herein provides a way for probing the effect of Ge inclusion in the Cu-Sn-S system thin films.
authors.affiliation: State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun, 130012 People's Republic of China.
authors.forename: Qingshuang
authors.initials: Q
authors.lastname: Liang
keywords: Compositionally controlled; Ge inclusion; Nanocrystals; Solar energy conversion; Tunable band gap