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Metal halide perovskites represent a promising class of gain media for next‐generation nonepitaxial laser diodes. However, fully electrically pumped perovskite laser diodes have not been achieved yet. Herein, the use of sodium fluoride (NaF) is explored as an efficient additive in halide perovskite films to improve their optical and light amplification properties. The incorporation of NaF in perovskites leads to a remarkable threefold increase in light‐emitting intensity. The threshold of amplified spontaneous emission (ASE) by optical pumping is reduced by more than 20%, from ≈13.5 to 10.4 μJ cm⁻². Furthermore, the NaF‐modified perovskites exhibit stable ASE emission, even after exposure to 1.5 billion optical pulses, highlighting substantial improvements in the material's photostability. Finally, optically pumped ASE is observed from a full perovskite light‐emitting diode stack, including lossy metal electrodes. This work demonstrates significant progress toward the development of electrically pumped perovskite lasers. 

Core/shell nanoparticles composed of a silica core over which a propargyl methacrylate (PMA) shell was polymerized around were synthesized. To employ the shell coating, the surface of the silica nanoparticles (SiNPs) was modified with an alkene-terminated organometallic silane linker that allowed for the covalent attachment of a poly(propargyl methacrylate) (pPMA) shell. The alkyne groups resulting from the pPMA shell were utilized in copper(I)-catalyzed azide/alkyne cycloaddition (CuAAC) reactions to attach azide-modified Förster resonance energy transfer (FRET) pairs of naphthalimide (azNap), rhodamine B (azRhod), and silicon phthalocyanine (azSiPc) derivatives to the shell surface. The luminescence of the system was manipulated by the covalent attachment of one, two, or three of the fluorophores resulting in no energy transfer, one energy transfer, or two energy transfers, respectively. When all three fluorophores were attached to the core/shell particles, an excitation of azNap with a wavelength of 400 nm resulted in the sequential energy transfer between two FRET pairs and the sole emission of azSiPc at 670 nm. These particles may have applications as bioimaging probes as their luminescence is easily detected using fluorescence microscopy. 

Electrochemical‐based memristors are highly attractive that are capable of nonvolatile analog tuning, long‐term state stability, low power consumption, device scalability, and fast switching speeds. Through the combination of film deposition techniques, i.e., vapor phase polymerization and screen printing, fabrication of a poly(4‐(6‐hexyl)‐4H‐dithieno[3,2‐b:2′,3′‐d]pyrrole) (p6DTP)‐based synaptic‐emulating three‐terminal memristor is designed. Through voltage‐driven pulse programming, and square waves with an amplitude of 100 mV and duration of 100 msec, the device exhibits a power consumption of 1 pJmm⁻²per synaptic event. By analyzing the fundamental operational trends of the p6DTP‐based device, simple and advanced integrated applications can be demonstrated along with synaptic‐like responses. This effort is the first presentation of the vapor phase polymerization technique for any dithienopyrrole‐based monomers, along with the physical implementation of any memristive system as an advanced logical circuit, demonstrated here as a cascaded combinational logic gate. 

Abstract A non‐volatile conjugated polymer‐based electrochemical memristor (cPECM), derived from sodium 4‐[(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐2‐yl)methoxy]butane‐2‐sulfonate (S‐EDOT), is fabricated through roll‐to‐roll printing and exhibited neuromorphic properties. The 3‐terminal device employed a “read” channel where conductivity of the water‐soluble, self‐doped S‐PEDOT is equated to synaptic weight and was electrically decoupled from the programming electrode. For the model system, a +2500 mV programming pulse of 100 ms duration resulted in a 0.136 μS resolution in conductivity change, giving over 1000 distinct conductivity states for one cycle. The minimum programming power requirements of the cPECM was 0.31 pJ mm⁻²and with advanced printing techniques, a 0.1 fJ requirement for a 20 μm device is achievable. The mathematical operations of addition, subtraction, multiplication, and division are demonstrated with a single cPECM, as well as the logic gates AND, OR, NAND, and NOR. This demonstration of a printed cPECM is the first step toward the implementation of a mass produced electrochemical memristor that combines information storage and processing and may allow for the realization of printable artificial neural networks. 

Abstract X‐ray radiation exhibits diminished scattering and a greater penetration depth in tissue relative to the visible spectrum and has spawned new medical imaging techniques that exploit X‐ray luminescence of nanoparticles. The majority of the nanoparticles finding applications in this field incorporate metals with high atomic numbers and pose potential toxicity effects. Here, a general strategy for the preparation of a fully organic X‐ray radioluminescent colloidal platform that can be tailored to emit anywhere in the visible spectrum through a judicious choice in donor/acceptor pairing and multiple sequential Förster resonance energy transfers (FRETs) is presented. This is demonstrated with three different types of ≈100 nm particles that are doped with anthracene as the scintillating molecule to “pump” subsequent FRET dye pairs that result in emissions from ≈400 nm out past 700 nm. The particles can be self‐assembled in crystalline colloidal arrays, and the radioluminescence of the particles can be dynamically tuned by coupling the observed rejection wavelength with the dyes' emission.