51�������

Abstract:

Mn ²⁺ ion doped 2D (PEA) ₂ PbBr ₄ perovskite nanocrystals with a high PLQY of 54% were synthesized using a crystallization method at room temperature, and efficient energy transfer from excitons to the Mn ²⁺ dopant was proven.

Abstract:

LED light bulbs that simulate solar spectrum were fabricated using CdSe core-shell quantum dots in combination with GaN blue-light chips. They exhibited excellent optical properties such as white CIE coordinates of (0.33, 0.33), high color rendering index (CRI) of 98 and correlated color temperature (CCT) of 5352 K. Moreover, a circuit system was used to control the LEDs so that the lighting spectrum changes with the time in a day to simulate the actual solar spectrum. The results show that the sun-like spectrum smart bulbs not only have good optical properties and high electrical stability, but also can automatically adjust their spectrum according to the time, making the lighting natural. This work makes sun-like lighting conditions for some special environments to promote the application of smart bulbs in smart lighting.

Abstract:

All‐inorganic perovskite materials are attractive alternatives to organic‐inorganic perovskites because of their potential for higher thermal stability. While CsPbI3 is compositionally stable under elevated temperatures, the cubic perovskite α‐phase is thermodynamically stable only at >330°C and the low‐temperature perovskite γ−phase is metastable and highly susceptible to non‐perovskite δ‐phase conversion in moisture. Many methods have been reported which show that incorporation of acid (aqueous HI) or “HPbI3” – recently shown to be dimethylammonium lead iodide (DMAPbI3) – lower the annealing temperature required to produce the black, perovskite phase of CsPbI3. The optical and crystallographic data presented here show that DMA can successfully incorporate as an A‐site cation to replace Cs in the CsPbI3 perovskite material. This describes the stabilization and lower phase transition temperature reported in the literature when HI or HPbI3 are used as precursors for CsPbI3. The Cs‐DMA alloy only forms a pure‐phase material up to ∽25% DMA; at higher concentrations the CsPbI3 and DMAPbI3 begin to phase segregate. These alloyed materials are more stable to moisture than neat CsPbI3, but do not represent a fully inorganic perovskite material.