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Spin-polarized electronic structures of VAlON centers consisting of an aluminum vacancy and a substitutional oxygen in AlN with different charge states are studied by first-principles calculations. It is observed that a paramagnetic neutral VAlON center is stable in p-type AlN. The defect center possesses a triplet ground state and a spin-conserved excited state with rather low excitation energy and its spin coherence time is in an order of second at T = 0 estimated by using a mean-field-based scheme. The results indicate that the neutral VAlON center is a promising candidate for spin coherent manipulation and qubit operation.

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A compressible supercapacitor is a promising energy storage device for wearable flexible electronic devices.

The demand for single photon emitters at λ=1.54  μm, which follows from the consistent development of quantum networks based on optical fiber technologies, makes Er:O centers in Si a viable resource, thanks to the I4→I4 optical transition of Er. While its implementation in high-power applications is hindered by the extremely low emission rate, the study of such systems in the low concentration regime remains relevant for quantum technologies. In this Letter, we explore the room-temperature photoluminescence at the telecomm wavelength from very low implantation doses of Er:O in Si. The lower-bound number of optically active Er atoms detected is of the order of 10, corresponding to a higher-bound value for the emission rate per individual ion of about 10 s.

We have demonstrated that it is possible to reproducibly quantify hydrogen concentration in the SiN layer of a SiO2/SiN/SiO2 (ONO) stack structure using ultraviolet laser-assisted atom probe tomography (APT). The concentration of hydrogen atoms detected using APT increased gradually during the analysis, which could be explained by the effect of hydrogen adsorption from residual gas in the vacuum chamber onto the specimen surface. The amount of adsorbed hydrogen in the SiN layer was estimated by analyzing another SiN layer with an extremely low hydrogen concentration (<0.2 at. %). Thus, by subtracting the concentration of adsorbed hydrogen, the actual hydrogen concentration in the SiN layer was quantified as approximately 1.0 at. %. This result was consistent with that obtained by elastic recoil detection analysis (ERDA), which confirmed the accuracy of the APT quantification. The present results indicate that APT enables the imaging of the three-dimensional distribution of hydrogen atoms in actual devices at a sub-nanometer scale.

The slope efficiency and threshold current density of 1.3 μm AlGaInAs/InP lasers with AlInAs–AlGaInAs multiquantum barrier (MQB) are experimentally studied and compared with the conventional step-index separate confinement heterostructure (SCH) laser. With the MQBs at the guiding layers, the characteristic temperature can be improved as much as 10 K as compared with the conventional SCH laser. This is attributed to the suppression of electron and hole leakage currents.

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