Colloidal CsPbX₃ (X = Br, Cl, and I) perovskite nanocrystals exhibit tunable bandgaps over the entire visible spectrum and high photoluminescence quantum yields in the green and red regions. However, the lack of highly efficient blue‐emitting perovskite nanocrystals limits their development for optoelectronic applications. Herein, neodymium (III) (Nd³⁺) doped CsPbBr₃ nanocrystals are prepared through the ligand‐assisted reprecipitation method at room temperature with tunable photoemission from green to deep blue. A blue‐emitting nanocrystal with a central wavelength at 459 nm, an exceptionally high photoluminescence quantum yield of 90%, and a spectral width of 19 nm is achieved. First principles calculations reveal that the increase in photoluminescence quantum yield upon doping is driven by an enhancement of the exciton binding energy due to increased electron and hole effective masses and an increase in oscillator strength due to shortening of the PbBr bond. Putting these results together, an all‐perovskite white light‐emitting diode is successfully fabricated, demonstrating that B‐site composition engineering is a reliable strategy to further exploit the perovskite family for wider optoelectronic applications.

Developing sophisticated strategies to stabilize oxidative metal catalysts based on the correlation between the dynamic oxidation state and the product profile is favorable for efficient electrochemical CO₂ conversion.

We show that solar cells, widely used in portable devices for power generation, can simultaneously extract a high-speed data signal in an optical wireless communication link. This Letter reports, to the best of our knowledge, the first use of an organic solar cell as an energy-harvesting receiver for visible light communications (VLCs). While generating maximum power in the cell, the communication link can deliver a data rate of 34.2 Mbps with a bit error rate of $4.08\times {10}^{-4}$ using an implementation of orthogonal frequency-division multiplexing. This approach could lead to printed optical data receivers in future eco-friendly VLC systems. Simultaneous functions of data communication and energy harvesting have great implications for the connectivity of future smart devices, many of which could become self-powered units as part of the “Internet of Things.”

Quantum dots are of growing interest as emissive materials in light-emitting devices. Here first we report the formation of highly luminescent organic capped colloidal cadmium sulfide (CdS) nanoparticles having the highest photoluminescence quantum yield of 69% in solutions and 34% in neat thin films in the near-infrared range. Second, we also show efficient electroluminescence in the near-infrared from solution processed hybrid light emitting diodes (LEDs) based on such colloidal CdS quantum dots embedded in an organic semiconductor matrix forming a nanocomposite active layer. We also discuss the device structure and role of the doped active layer in efficiency improvement. With optimized active layer thickness and concentration of QDs, the device exhibits an external electroluminescence quantum efficiency of 0.62% at a peak emission wavelength of 760 nm, providing a route to solution processable flexible light sources for biosensors and medicine.