Cu2+ doped CsPb(Cl/Br)3 quantum dots glasses for high performance long wavelength pass filters in the blue-purple region

Abstract

The CsPb(Cl/Br)3 quantum dots (QDs) with high Cl content are difficult to precipitate in the glass matrix, which hiders the development of the long wavelength pass filter operating in blue-purple region. In this work, the Cu2+ doped CsPb(Cl/Br)3 QDs glasses have been fabricated in the borate glass matrix by melt quenching process. To increase the Cl content, high Cl/Br ratio is used, and a crucible cover is used during the melting process to reduce Cl volatilization. The transmittance (T%), optical density (OD), photoluminescence (PL), PL excitation (PLE) and PL decay have been evaluated. The working wavelength of filters has been extended from ~500 nm to 412 nm. Small amount Cu2+ of 0.005–0.3 mol % is used for PL quenching and meanwhile maintaining excellent properties in transmittance and OD. As Cu2+ concentration increases, the PL intensity is quenched and the PL lifetime is decreased for the CsPb(Cl/Br)3 QDs. Quenching mechanism is considered as energy dependent electron transfer (ET). The fabricated CsPb(Cl/Br)3 QD glasses can meet requirements for the long wavelength pass filters in the blue-purple region.