Colloidal synthesis of functionalized CdSe/CdS@ZnO nanoplatelets and their potential application as sensors

Atomically precise two-dimensional semiconductor nanoplatelets (NPLs) have attracted enormous attention due to their low-cost solution processing and outstanding optoelectronic properties. However, the challenges in organic-inorganic interfaces between surface ligands and NPLs are the poor passivation effect, limited charge translation, and low working stability in the active layer. Herein, the functionalized CdSe/CdS@ZnO NPLs were constructed with the inorganic ZnO sol by a facile solution process. We demonstrated that the introduction of inorganic sol to passivate surface defects and improve the optical stability of NPLs. Meanwhile, the inorganic ZnO hosts could effectively enhance the electroconductibility of NPLs film, thus boosting the charge transport capacity in active layer. Besides, the CdSe/CdS@ZnO NPLs as the active layer exhibited the obvious optical response for electric current signal. The emission intensity of NPLs layer was reduced to below ∼50% of their initial intensity with increasing driving current. These results suggest that the functionalized surface with inorganic sol is feasible and can pave the way for future commercial applications of all-inorganic NPLs in next-generation optoelectronic sensors.