A Novel Microsteganography Technique Leveraging Engineered Relaxation Pathways of High-Energy Excitons in Monolayer WSe₂

In the age of information overload, protecting sensitive data demands reliable solutions, with multidimensional optical encryption emerging as a transformative technology. Wavelength, a critical parameter of light, holds significant potential for developing highly secure encryption systems that restrict information access to specific illumination conditions, further enhancing data security. However, the encryption technology related to wavelength is still in its nascent stages. Here, we report a breakthrough wavelength-dependent microsteganography technique based on a monolayer WSe₂/CdSe quantum dots heterostructure. By precise modulation of the band alignment to engineer the relaxation pathways of high-energy excitons in WSe₂, the heterostructure encodes information that is selectively activated by a specific wavelength of light. Furthermore, the incorporation of Morse code encryption seamlessly merges spectral selectivity with enhanced information complexity, creating a dual-layer security mechanism. This work not only advances the field of optical encryption but also opens new avenues for applications in secure data storage and transmission.