Mn²⁺‐Doped CsPbI₃ Nanocrystals for Perovskite Light‐Emitting Diodes with High Luminance and Improved Device Stability

Abstract

Cubic α‐CsPbI3 has promising applications in the optoelectronic field for its excellent properties. However, α‐CsPbI3 black phase is instable at room temperature and easily converts into nonluminescent yellow orthorhombic phase (δ‐CsPbI3). Herein, the stability of α‐CsPbI3 is significantly improved by incorporating Mn2+ dopants into the perovskite lattice. Mn2+: CsPbI3 has essentially the same crystal structure as the parent α‐CsPbI3, and Mn2+ doping can promote photoluminescence quantum yield (PLQY) from 55% to 93%. Importantly, Mn2+: CsPbI3 can maintain 60% PLQY after exposing in air for 45 days, whereas the undoped CsPbI3 completely loses its luminescence in 10 days. First‐principles calculations testify that improved stability and optical properties of Mn2+: CsPbI3 are primarily attributed to the increased formation energy and tolerance factor. Accordingly, the luminance, external quantum efficiency (EQE), and T 50 lifetime of Mn2+: CsPbI3 perovskite light‐emitting diode (PeLED) reach 1066 cd m−2, 1.8%, and 2500 s, whereas the values for the undoped counterpart are only 415 cd m−2, 0.6%, and 140 s, respectively. In addition, it is evidenced that introducing a LiF buffer layer between hole transport layer and perovskite emissive layer can further boost the device performance, particularly, the luminance and T 50 lifetime achieve 1394 cd m−2 and 225 min at 140 cd m−2.

CsPbBr3:Mn Nanowires: d-d Transfer of Mn Ions for Bright White Emitting Diodes

“…In recent years, numerous methods, such as heat injection, ligand replication and reprecipitation, spin coating, microemulsion, as well as cutting-edge ultrasound, have been employed to prepare all-inorganic perovskite nanomaterials. − Perovskite nanomaterials with different morphologies and sizes, such as zero-dimensional (0D) perovskite quantum dots, one-dimensional (1D) nanowires (NWs) or nanorods, , and two-dimensional (2D) nanoplates, have been devised and synthesized by regulating the experimental conditions, including temperature, reaction time, capping agents, ion ratios, and templates. Compared with 3D and 2D nanomaterials, 1D perovskite materials have a high specific surface area and powerful quantum confinement effect, thus enriching their unique optical and physical characteristics.…”

Healthy and stable lighting via single-component white perovskite nanoplates

“…S2 †), which was due to the lattice shrinking by replacing Pb 2+ with small-sized Mn 2+ . 4,45,46 According to their PL spectra (Fig. 2b), these white lights consist of two complementary colors, skyblue (482 nm) and orange-red (610 nm), which are attributed to the band edge emission of CsPbBr 3 NPLs and the ionic emission of Mn 2+ , respectively.…”

Mn-derived Cs4PbX6 nanocrystals with stable and tunable wide luminescence for white light-emitting diodes

“…Mn ion doping in semiconductor materials not only results in new luminescence peaks, which are generated by energy transfer from the host to Mn ions, but also reduces the density of defect states and improves the PLQY and stability. 33–37 Therefore, metal halide perovskites with Mn ion doping have become a hot research topic. For example, David Parobek et al 38 reported Mn-doped CsPbCl 3 and CsPb(Cl/Br) 3 NCs, showing strong sensitized Mn luminescence.…”