The synergistic effect of h-BN/c-BN/EP on the enhancement of thermal conductivity of polymeric composites has been demonstrated.

The gaseous chiral differentiation of alanine by permethylated β-cyclodextrin was studied using IRMPD spectroscopy and density functional theory calculations. The protonated non-covalent complexes of permethylated β-cyclodextrin and d- or l-alanine were mass-selected and investigated by IR laser pulses in the wavelength region of 2650-3800 cm. The remarkably different features of the IRMPD spectra for d- and l-alanine are described, and their origin is elucidated by quantum chemical calculations. We show that the differentiation of the experimentally observed spectral features is the result of different local interactions of d- and l-alanine with permethylated β-cyclodextrin. We also assign the extremely high-frequency (>3700 cm) bands in the observed spectra to the stretch motions of completely isolated alanine -OH groups.

High quality hexagonal boron nitride (h‐BN) thick films are indispensable for practical deep‐ultraviolet (DUV) photodetector applications. However, the controllable synthesis of h‐BN films in terms of thickness and crystallinity often requires high growth temperatures, tedious chemical precursors and, catalytic transition metal substrates, that will eventually hinder their applicability. In this work, the direct growth of h‐BN films with thickness of 50–500 nm on silicon(100), sapphire, and quartz substrates by ion beam assisted deposition at a lower temperature (≈500 °C) without employing extra catalysis is reported. The as‐synthesized h‐BN thick films are stoichiometric, smooth, and continuous without obvious pinholes and cracks, consisting of nanocrystalline domains on the dielectric substrates, distinct from those grown on metallic substrates. More intriguingly, the DUV photodetector fabricated from a 500 nm thick h‐BN film on quartz substrate exhibits high peak responsivity (0.5 A W−1) with a ultrahigh on/off ratio of >103 at 204 nm, a high rejection ratio (R204nm/R250nm > 103), a large specific detectivity (6.92 × 109 Jones), and a sharp cutoff wavelength at 218 nm. The work herein demonstrates the great potential of this form of h‐BN thick films toward the development of DUV photodetectors.

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