Stable CsPbBr₃ Achieved by Porphyrin–Thiol Surface Management and Their Dual‐Stimuli Responsive for Optical Encoding

Abstract Surface ligand management plays an essential role in improving the stability of perovskite quantum dots (QDs) and endowing them with novel property. Herein, a red fluorescence porphyrin‐thiol (named Por‐SH) is applied to adjust the surface and stimuli responsiveness of CsPbBr₃ QDs. According to the theoretical and experimental results, Por‐SH can bind tightly to the exposed Pb of CsPbBr₃ QDs, thus leading to the formation of Por‐SH‐QDs with an excellent resistance to water and UV light. Moreover, CsPbBr₃ act as energy donors to improve the photoresponse of Por‐SH through energy transfer, especially when heated. Notably, the Por‐SH and QDs behave differently in terms of response to the temperature in the Por‐SH‐QDs system. Therefore, the Por‐SH‐QDs are capable of reversible stimuli–response property in the presence of heat/cool stimuli when excited by UV light. Finally, the disposable or reversible optical encoding label based on Por‐SH‐QDs and QDs is obtained by combining stability and the responsiveness to stimuli. Through the selection of suitable ligands, the surface of QDs is efficiently managed, which can not only mitigate instability but also endow perovskite QDs with the responsiveness to stimuli.