Magnetism coupled with topological materials can offer a platform for realizing quite rich fascinating physical phenomena, including quantum anomalous Hall effect (QAHE), topological magnetoelectric effect, and giant anomalous Nernst effect. Recently, the discovery of the intrinsic magnetic topological insulator ${\mathrm{MnBi}}_2{\mathrm{Te}}_4$ has promoted the study of the physical phenomena of magnetic topological materials. Here, we grow single crystals of Sn-doped ${\mathrm{MnBi}}_2{\mathrm{Te}}_4$ in bulk with ratios of 25%, 33%, 50%, and 66% to probe the magnetic and electrical properties. We perform low-temperature magnetic and electrical transport measurements for Sn-doped ${\mathrm{MnBi}}_2{\mathrm{Te}}_4$ and find that the antiferromagnetic (AFM) character is clear in this material until the concentration rises to 66%, and mainly transport dominated carriers are n-type. Most of all, the transition points of ${\mathrm{MnBi}}_2{\mathrm{Te}}_4$ decrease upon Sn doping, providing an alternative approach to realize QAHE at lower magnetic field, which is essential for further application in AFM spintronics.

High-performance organic semiconductors should have good spectral absorption, a narrow energy gap, excellent thermal stability and good blend film morphology to obtain high-performance organic photovoltaics (OPVs). Therefore, we synthesized two IDTz-based electron acceptors in this research. When they were blended with donor PTB7-Th to prepare OPV devices, the PTB7-Th:IDTz-BARO-based binary OPVs exhibited a power conversion efficiency (PCE) of 0.37%, with a short-circuit current density (J_sc) of 1.24 mA cm⁻², a fill factor (FF) of 33.99% and an open-circuit voltage (V_oc) of 0.87 V. The PTB7-Th:IDTz-BARS-based binary OPVs exhibited PCE of 4.39%, with J_sc of 8.09 mA cm⁻², FF of 54.13% and V_oc of 1.00 V. The results show the strong electronegativity terminal group to be beneficial to the construction of high-performance OPV devices. Highlights: (1) Two new acceptors based on 5,5′-(4,4,9,9-tetrakis (4-hexylphenyl)-4,9-dihydro-s-indaceno [1,2-b:5,6-b′] dithiophene-2,7-diyl) dithiazole (IDTz) and different end groups (BARS, BARO) were synthesized; (2) BARS and BARO are electron-rich end groups, and the electron acceptors involved in the construction show excellent photoelectric properties. They can properly match the donor PTB7-Th, and show the appropriate surface morphology of the active layer in this work; (3) Compared with IDTz-BARO, IDTz-BARS has deeper LUMO and HOMO energy levels. In combination with PTB7-Th, it shows 4.39% device efficiency, 8.09 mA cm⁻² short-circuit current density and 1.00 V open circuit voltage.