A facile approach to hetero-nanorods of Ag₂Se-MSe (M = Cd, Zn) with enhanced third-order optical nonlinearity

Semiconductor-semiconductor hetero-nanorods (Ag₂Se-CdSe and Ag₂Se-ZnSe) with high crystallinity have been synthesized by a facile and low-cost method. High resolution transmission electron microscopy investigations reveal that the growth follows a catalyst-assisted mechanism. A preliminary investigation of nonlinear optical properties shows that the hetero-nanorods exhibit significantly enhanced third-order nonlinear optical properties. The free carrier absorption cross-section of Ag₂Se-CdSe hetero-nanorods is one order of magnitude higher than that of the corresponding single component CdSe nanocrystals. The results obtained in this study represent a new approach to the design and construction of metal selenide hetero-nanorods with high crystallinity and enhanced nonlinear optical capabilities.