Sub-1 nm Spectral Regulation of Perovskite Quantum Dots via Brownian Motion Collision Driven Anion Exchange

The excellent optoelectronic properties of perovskite quantum dots (PeQDs) have great potential in fields such as display, sensing, and encryption. However, the variable application scenarios present challenges to the range and accuracy of their spectral regulation. Here, a Brownian motion collision driven anion exchange strategy is proposed to achieve refined spectral regulation of PeQDs. By modulation of the ionic binding energy of halide particles and PeQDs and control of their collision intensity, the reaction rate and degree of anion exchange can be finely regulated. Consequently, the spectral resolutions of 0.392, 0.238, and 0.550 nm are achieved in the ranges of 470.4-480.2, 514.6-526.3, and 640.3-650.3 nm, respectively. The method can be used to fabricate filters for optical sensing chips. The photoresponse curves reached resolutions of 0.89, 1.15, and 1.39 nm within the ranges of 466.1-481.2, 536.0-553.2, and 677.3-698.1 nm, respectively, demonstrating the potential of this work in the field of spectral sensing.