Broadband Photoresponse Enhancement by Band Engineering in Sb-Doped MnBi2Te4

• DOI: 10.1021/acsphotonics.4c02182
• Publication Date: 2025-02-07T06:01:51Z
• Authors: Zixuan Xu; Haonan Chen; Jiayu Wang; Yicheng Mou; Yingchao Xia; Jiaming Gu; Yuxiang Wang; Qi Liu; Jiaqi Liu; Wenqing Song; Qing Lan; Tuoyu Zhao; Wu Shi; Cheng Zhang
• Keywords: Condensed Matter - Materials Science; Condensed Matter - Mesoscale and Nanoscale Physics; Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences

Topological materials have attracted considerable attention for their potential in broadband and fast photoresponses, particularly the infrared regime. However, high carrier concentration these systems often leads to rapid recombination of photogenerated carriers, limiting photoresponsivity. Here, we demonstrate that Sb doping MnBi2Te4 effectively reduces suppresses electron–hole recombination, thereby significantly improving optoelectronic performance across visible mid-infrared spectra. The optimally doped Mn(Bi0.82Sb0.18)2Te4 photodetector achieves a responsivity 3.02 mA W–1 with response time 18.5 μs at 1550 nm, 0.795 9.0 4 μm. These values represent nearly 2 orders magnitude improvement compared undoped MnBi2Te4. Our results highlight band engineering as an effective strategy enhance topological material-based photodetectors, opening new avenues high-sensitivity detection.