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Abstract: It is very important to develop ambipolar field effect transistors to construct complementary circuits. To obtain balanced hole‐ and electron‐transport properties, one of the key issues is to regulate the energy levels of the frontier orbitals of the semiconductor materials by structural tailoring, so that they match well with the electrode Fermi levels. Five conjugated copolymers were synthesized and exhibited low LUMO energy levels and narrow bandgaps on account of the strong electron‐withdrawing effect of the carbonyl groups. Polymer thin film transistors were prepared by using a solution method and exhibited high and balanced hole and electron mobility of up to 0.46 cm2 V−1 s−1, which suggested that these copolymers are promising ambipolar semiconductor materials. [ABSTRACT FROM AUTHOR]

Perovskite compounds are always the focus in the material research field. Herein, the polycrystalline samples and single crystals of Na 2 ZrTeO 6 , a B-site ordered double-perovskite compound, were prepared successfully. Single crystal X-ray diffraction demonstrated that Na 2 ZrTeO 6 crystallizes in the cubic space group Fm-3m (No. 225) with unit parameters of a = b = c = 7.80360(10) Å. The crystal structure of Na 2 ZrTeO 6 , formed by ZrO 6 and TeO 6 octahedra through sharing the corner oxygen atoms, belongs to the typical rock-salt-type perovskite structure. The density functional theory calculations show that Na 2 ZrTeO 6 has a direct band gap with band gap of 3.21 eV, which is lower than the experimental value of 3.85 eV. Interestingly, the powder samples of Na 2 ZrTeO 6 exhibit a self-activated near-infrared emission centered at 780 nm under ultraviolet light excitation. And a strong luminescence thermal stability was also observed. Compared to room temperature, the luminescence intensity can maintain 64 % at 200 °C. [Display omitted] • The high-purity double-perovskite Na 2 ZrTeO 6 samples were synthesized by wet chemical method. • Structure analysis indicate that Na 2 ZrTeO 6 belongs to the typical rock-salt-type perovskite structure. • Na 2 ZrTeO 6 exhibits self-activated near-infrared emission centered at 780 nm excited by 308 nm. • The sample's emission intensity maintained 64 % of its room temperature peak intensity at 200 °C. [ABSTRACT FROM AUTHOR]

A new mixed-anion phosphate crystal Cs 2 Bi 2 Sr(P 2 O 7)(PO 4) 2 was obtained by molten salt method. Single-crystal X-ray diffraction data demonstrated that the compound crystallizes in monoclinic space group P 2 1 /c (No.14) with unit cell parameters a ​= ​17.708(10) Å, b ​= ​9.156(5) Å and c ​= ​9.221(5) Å, β ​= ​90.160(8) °. The structure exhibits a novel three-dimensional network, which is made up of BiO 6 , BiO 5 , SrO 6 and CsO 11 polyhedra sharing the corners with PO 4 tetrahedra and P 2 O 7 diphosphate groups. The band gap was estimated by the combined density functional theory and experimental study. Photoluminescence property of Cs 2 Bi 2- x Sr(P 2 O 7)(PO 4) 2 : x Eu3+ showed the excellent thermal stability and high quantum efficiency. The structure of a new mixed-anion phosphate Cs 2 Bi 2 Sr(P 2 O 7)(PO 4) 2 , belonging to a rare case with twinning structure, is herein reported. And the photoluminescence of Eu3+ doped Cs 2 Bi 2 Sr(P 2 O 7)(PO 4) 2 shows high quantum efficiency (92%). Image 1 • The structure of Cs 2 Bi 2 Sr(P 2 O 7)(PO 4) 2 (CBSP) exhibits rare twin structure. • The new CBSP crystals were firstly obtained using molten salt method. • The CBSP:0.25Eu3+ shows excellent thermal stability and high quantum efficiency. [ABSTRACT FROM AUTHOR]