The achievement of size uniformity and monodispersity in perovskite quantum dots (QDs) requires the implementation of precise temperature control and the establishment of optimal reaction conditions. Nevertheless, the accurate control of a range of reaction variables represents a considerable challenge. This study addresses the aforementioned challenge by employing manganese (Mn) doping to achieve size uniformity in CsPbBr 3 perovskite QDs without the necessity for the precise control of the reaction conditions. By optimizing the Mn:Pb ratio, it is possible to successfully dope CsPbBr 3 QDs with the appropriate concentrations of Mn²⁺ and achieve a uniform size distribution. The spectroscopic measurements on single QDs indicate that the appropriate Mn²⁺ concentrations can result in a narrower spectral linewidth, a longer photoluminescence (PL) lifetime, and a reduced biexciton Auger recombination rate, thus positively affecting the PL properties. This study not only simplifies the size control of perovskite QDs but also demonstrates the potential of Mn-doped CsPbBr 3 QDs for narrow-linewidth light-emitting diode applications.
Bi Yuhe,Sun Jianhui,Cao Sheng,Li Qiuyan,Zheng Jinju,Yuan Xi,Wang Yunjun,Zou Bingsuo,Zhao Jialong
As next-generation display technologies, eco-friendly colloidal quantum dot light-emitting diodes have drawn great attention due to their excellent luminescence properties, along with their rapid development. However, practical applications of eco-friendly quantum dot light-emitting device remain challenging, primarily due to the inferior performance of green device, which still lag behind their red and blue counterparts. Herein, we present efficient green device based on interfacial potential-graded ZnSeTe quantum dots. Our findings show that this potential-graded structure alleviates interfacial lattice mismatch and strain, reducing structural deformation and misfit defects. The smoothed interfacial potential suppresses the nonradiative recombination processes, particularly Auger recombination revealed by excitation-intensity dependent ultrafast transient absorption kinetics. Consequently, the interfacial potential-graded quantum dots demonstrate highly efficient green quantum dot light-emitting diodes, with a peak external quantum efficiency of 21.7% at 520 nm and a corresponding current efficiency of 75.7 cd A −1 .