Laser-induced fabrication of highly branched CuS nanocrystals with excellent near-infrared absorption properties**Project supported by National Natural Science Foundation of China (Grant Nos. 11575102, 11105085, 11405098, and 11375108) and the Fundamental Research Funds of Shandong University, China (Grant No. 2015JC007).

Abstract

We report on the successful fabrication of highly branched CuS nanocrystals by laser-induced photochemical reaction. Surprisingly, the single-crystalline nature with preferential alignment of the (107) orientation can be well improved during the moderate growth process. The branch length drastically increases from about 5 nm to 6 μm with an increase of photochemical reaction time (0–40 min). The absorption spectra of as-prepared CuS nanodendrites show that localized surface plasmon resonance (LSPR) peaks can be modulated from about 1037 nm to 1700 nm with an increase of branch length. Our results have a promising potential for photodynamic therapy and biological imaging application.