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 CsPbBr₃ 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 CsPbBr₃ 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 CsPbBr₃ QDs for narrow-linewidth light-emitting diode applications.

Determining the correlation between the size of a single quantum dot (QD) and its photoluminescence (PL) properties is a challenging task. In the study, we determine the size of each QD by measuring its absorption cross section, which allows for accurate investigation of size-dependent PL blinking mechanisms and volume scaling of the biexciton Auger recombination at the single-particle level. A significant correlation between the blinking mechanism and QD size is observed under low excitation conditions. When the QD size is smaller than their Bohr diameter, single CsPbI3 perovskite QDs tend to exhibit BC-blinking, whereas they tend to exhibit Auger-blinking when the QD size exceeds their Bohr diameter. In addition, by extracting bright-state photons from the PL intensity trajectories, the effects of QD charging and surface defects on the biexcitons are effectively reduced. This allows for a more accurate measurement of the volume scaling of biexciton Auger recombination in weakly confined CsPbI3 perovskite QDs at the single-dot level, revealing a superlinear volume scaling (τXX,Auger ∝ σ1.96).

The fast crystallization and facile oxidation of Sn²⁺ of tin-lead (Sn-Pb) perovskites are the biggest challenges for their applications in high-performance near-infrared (NIR) photodetectors and imagers. Here, we introduce a multifunctional diphenyl sulfoxide (DPSO) molecule into perovskite precursor ink to response these issues by revealing its strong binding interactions with the precursor species. The regulated perovskite film exhibits a dense morphology, reduced defect density and prolonged carrier diffusion length. The manufactured self-powered photodetector realizes a spectral response of 300-1100 nm, dark current density of 4.7 × 10⁻⁸ mA cm⁻², peak responsivity of 0.49 A W⁻¹ and specific detectivity of 1.20 × 10¹² Jones in NIR region (780–1100 nm), –3 dB bandwidth of 11.4 MHz, linear dynamic range of 174 dB, and ultrafast rise/fall time of 14.2/17.1 ns, respectively. We demonstrate a 64 × 64 NIR imager with an impressive spatial resolution of 1.32 lp mm⁻¹ by monolithically integrating the photodetector with a commercial thin-film transistor readout circuit.