Colloidal semiconductor nanocrystals: synthesis, optical nonlinearity, and related device applications

The rapid development of photonic devices requires the exploration of novel materials with superior nonlinear optical (NLO) properties. Colloidal semiconductor nanocrystals (NCs) exhibit size-tunable exciton resonances and excellent NLO properties. Besides, the preparation methods of colloidal semiconductor NCs are facile and NCs can be easily assembled into films by low-cost and large-area solution processing. These characteristics make colloidal semiconductor NCs promising for nonlinear photonic device applications. This review provides the recent advances of colloidal semiconductor NCs in nonlinear optics and ultrafast photonics. The main liquid-phase synthetic methods, third-order NLO properties, and related nonlinear photonic device applications of several colloidal semiconductor NCs are discussed. The potential challenges and a perspective of the future research areas of these colloidal semiconductor NCs for nonlinear optics and ultrafast photonics are presented.