We report an enhanced thermoelectric performance by manipulating band engineering in Mn−In codoped SnTe. It has been revealed that SnTe is a unique example achieving the synergy of band convergence and resonant state. According to band theory, band convergence favors heavy doping, while resonant state favors light doping. Following this idea, a series of Mn−In codoped SnTe samples are prepared by hot pressing. A significantly enhanced Seebeck coefficient of 116 μ V K − 1 at 300 K is observed in Sn 0.915 Mn 0.11 In 0.005 Te. By carefully tuning the band structure of the solid solution, we achieve a high ZT max of 1.15 at 823 K and an overall enhanced ZT ave of 0.62. The improved thermoelectric performance in a large temperature range leads to a competitive conversion efficiency of 10.1% with T c = 300 K and T h = 850 K, suggesting Mn−In codoped SnTe is a promising candidate for medium-temperature thermoelectric applications.

In the field of clinical diagnosis, it is important to construct a potential-resolved multiplex electrochemiluminescence (ECL) biosensor for decreasing the false-positive rate and improving the diagnostic accuracy. However, the shortage of low-potential cathodic luminophores between −1 and 0 V (vs Ag/AgCl) severely limited the development of the biosensor. Herein, we synthesized a novel luminophore N,N-bis-(3-dimethyl aminopropyl)-3,4,9,10-perylene tetracarboxylic acid diimide (PDI), which gave dual emissions at −0.25/–0.26 V with K2S2O8 as a co-reactant in aqueous solution. The ECL was assigned to excited J-type PDI dimers. Then, PDI and luminol were used as luminophores to respectively combine with graphite oxide and gold nanoparticles and form potential-resolved ECL nanoprobes. Also, this potential-resolved ECL nanoprobes were respectively functionalized by secondary antibodies (Ab2) to construct a low-potential sandwiched ECL immunosensor for tumor markers carcinoembryonic antigen (CEA) and α-fetoprotein (AFP) simultaneous determination during linear scanning potential range from −0.6 to 0.6 V. The prepared multiplex immunosensor exhibited sensitive ECL response for CEA at −0.6 V due to PDI and that for AFP at 0.6 V due to luminol, and both linear semilogarithmical ranges were from 0.1 pg to 1 ng mL–1. In addition, PDI with dual ECL peaks showed enticing prospect of built-in self-calibration for a precise quantitative and bioimaging analysis.

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α‐MgAgSb is recently discovered to be a new class of thermoelectric material near room temperature. A competitive ZT of 1.4 at 525 K is achieved in Ni‐doped α‐MgAgSb, and the measured efficiency of energy conversion reaches a record value of 8.5%, which is even higher than that of the commercially applied material bismuth telluride. On the other hand, the band structure of α‐MgAgSb is believed to be unprofitable to the power factor, owing to the less degenerate valence valleys. Here, this paper reports a systematic theoretical study on the thermoelectric properties by using the electron/phonon structure and transport calculations. Based on the careful analysis of Fermi surface, a principled scheme is presented to design band engineering in α‐MgAgSb. Following the given rules, several effective dopants are predicted. As two examples, Zn‐ and Pd‐doped α‐MgAgSb are numerically confirmed to exhibit an extraordinary ZT value of 2.0 at 575 K and a high conversion efficiency of 12.6%, owing to the effects of band convergence. This work develops an applicable scheme for the purposive design of band engineering, and the idea can be simply applied to more thermoelectric materials.

The hot deformation process enhances the textured degree of ploycrystalline SnSe, leading to better electrical conductivity and a high power factor of 10.2 μW cm−1 K−2 at 823 K.