Lead halide perovskites (MAPbX3, X = Cl, Br, I) have garnered significant attention for their potential in highperformance photovoltaics and light-emitting diodes, but their stability under analytical conditions remains a concern. In this study, we systematically investigate the denaturation processes of MAPbX3 employing different analytical methods, including X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, reflection electron energy loss spectroscopy, and ambient pressure XPS. The samples were exposed to X-ray and electron beam irradiation in ultra-high vacuum (UHV) and reactive gas environments (O2 and H2O). The denaturation process, characterized by the growth of Pb0 and Pb-Ox species, is most pronounced in MAPbCl3, followed by MAPbBr3, and least in MAPbI3. Furthermore, MAPbX3 samples exhibited distinct behaviors under exposure to different environments: MAPbCl3 and MAPbBr3 shows notable Pb-Ox formation in an O2 atmosphere, while MAPbI3 displays minimal oxidation. A comparative X-ray diffraction analysis revealed that low crystallinity was associated with high denaturation, even among MAPbX3 samples with identical compositions. Collectively, these findings emphasize the importance of considering both halogen composition and physical properties, such as crystallinity and morphology, when assessing the stability and reliability of lead halide perovskite materials for optoelectronic applications.

High dielectric constant (k) materials have been investigated to improve the performance of dynamic random access memory (DRAM) capacitors. However, the conventional binary oxides have reached their fundamental limit of k < 100. In this study, we investigated alternative ternary oxides, SrTiO3 (STO) and (Ba,Sr)TiO3 (BSTO), which were epitaxially grown on SrRuO3 (SRO) using atomic layer deposition (ALD). The structural compatibility between SRO and STO enables the in situ crystallization of STO during ALD at a low temperature of 300 degrees C. Consequently, STO on SRO exhibited no film deformation, a common issue during high temperature postdeposition annealing, and maintained superior crystallinity at a thin thickness down to 50 & Aring;. Furthermore, the dielectric constant of STO can be adjusted by modulating its tunable ferroelectric and dielectric properties through Ba doping. BSTO, with a high dielectric constant (k(max):527) achieved at a Ba doping concentration of approximately 50%, displayed a low leakage current density (3.9 x 10(-8) A cm(-2) @ 1 V) and demonstrated excellent reliability of 10(12) cycles in the metal-insulator-metal capacitors. This study proposes a promising alternative to satisfy the extreme EOT required for next-generation DRAM capacitors.

A novel green-absorbing organic molecule featuring dual intramolecular chalcogen bonds is synthesized and characterized. This molecule incorporates two such bonds: one between a tellurium atom and the oxygen atom of a carbonyl moiety, and the other between the tellurium atom and the adjacent nitrogen atom within a pyridine moiety. The molecule, featuring dual intramolecular chalcogen bonds exhibits a narrow absorption spectrum and elevated absorption coefficients, closely aligned with a resonance parameter of approximately 0.5. This behavior is due to its cyanine-like characteristics and favorable electrical properties, which are a direct result of its rigid, planar molecular structure. Therefore, this organic molecule forming dual intramolecular chalcogen bonds achieves superior optoelectronic performance in green-selective photodetectors, boasting an external quantum efficiency of over 65% and a full-width at half maximum of less than 95 nm while maintaining the performance after 1000 h of heating aging at 85 °C. Such organic photodetectors are poised to enhance stacked organic photodetector-on-silicon hybrid image sensors, paving the way for the next-generation of high-resolution and high-sensitivity image sensors.

Negative differential capacitance in ferroelectrics, which can be stabilized using a dielectric, could be used to overcome the limitations of capacitive coupling in electronic devices. However, the use of negative differential capacitance in scaled silicon-based structures—such as those used in advanced low-power logic devices—remains challenging. Here we report the electrical performance enhancement due to negative differential capacitance in metal–oxide–semiconductor capacitors based on ferroelectric zirconium-doped hafnia (Hf 0.5 Zr 0.5 O 2 ) with a thickness down to 1 nm. The devices exhibit superior performance to physically thinner control devices without the ferroelectric zirconium-doped hafnia. An S-shaped polarization–electric field relation verifies the negative differential capacitance effect. The effect is also achieved in field-effect transistors in which high- κ hafnia is replaced with the ferroelectric zirconium-doped hafnia, leading to an increase in on current and decrease in off current along with negative drain-induced barrier lowering. The negative differential capacitance exhibits endurance over more than 10 15 cycles and can be tuned using doping that controls the interface charges.

In this study, to understand the effect of sublayer thickness of doped HfO2 films with limited dopant solubility on ferroelectric phase stabilization, nanolaminated HfO2–Al2O3 films with various sublayer thicknesses were prepared through atomic layer deposition (ALD), and the phase evolution behavior of these films with increasing post-metallization annealing (PMA) temperature was investigated. A narrow optimal range of the HfO2 sublayer thickness was required to achieve facile crystallization into a tetragonal phase, followed by orthorhombic phase transformation through sufficient Al diffusion. Because the Al2O3 sublayer cannot be completely dissolved, it should be as thin as possible so that it can easily agglomerate to provide an effective connection between the HfO2 sublayers during the PMA process. When stabilizing the ferroelectric phase of HfO2 films by mixing with dopants with limited solubility, the thicknesses of the HfO2 and Al2O3 sublayers in the nanolaminated form were revealed to be more critical than the nominal doping concentration inferred from their thickness ratios (ALD cycle ratios).