Excellent long-wavelength-pass filters of CsPbBr3 and CsPb(Cl/Br)3 quantum dot glasses by a Cu2+ quenching strategy

Abstract

Perovskite C s P b B r 3 quantum dot (QD) glasses doping C u 2 + are reported for excellent long-wavelength-pass filters. Transmittance, optical density (OD), photoluminescence (PL), PL excitation, and PL decay are used to investigate filter properties and the quenching mechanism. At low C u 2 + molar concentrations of 0%, 0.0025%, 0.005%, and 0.01%, the filters exhibit good properties in transmittance and OD. Transition wavelengths are 518, 513, 513, and 512 nm, respectively. The shape and position of transmittance and OD are almost not changed. As C u 2 + concentration increases, PL intensity is monotonously quenched. PL decay is obviously faster. The quenching mechanism is dynamic quenching, which is electron transfer from QDs to C u 2 + . In comparison with the initial intensity, the intensity decreases by factors of 7.6, 12.8, and 18.8. Oxidation and reduction atmospheres are introduced, and the dynamic quenching mechanism is further confirmed. At high C u 2 + concentrations of 0.013%–0.02%, the quenching mechanism is static quenching. Double-anion C s P b ( C l / B r ) 3 QD glasses of different C u 2 + concentrations extend the operation wavelength to the blue light region. For C u 2 + concentrations of 0%, 0.005%, and 0.01%, the transition wavelengths are 470, 472, and 473 nm for C s P b ( C l / B r ) 3 (NaCl as Cl source) QD glasses, and 430, 426, and 445 nm for C s P b ( C l / B r ) 3 ( P b C l 2 as Cl source) QD glasses, respectively.