Low-Noise Te/MoTe 2 Heterojunction Waveguide-Integrated Photodetector

作者：Hui Ma, Shuo Lin, Ting He, Bo Tang, Jianghong Wu, Yunpeng Wang, Yuting Ye, Jialing Jian, Jiacheng Wang, Zuocheng Zhang, Maoliang Wei, Yalan Si, Yongyu Wu, Junying Li, Xvsheng Qiao, Dawei Gao, Lan Li, Weida Hu, Hongtao Lin · 发表于：ACS Photonics · 年份：2024 · DOI：10.1021/acsphotonics.4c00370 · 被引用次数：6 · 研究领域：Photonic and Optical Devices、Photorefractive and Nonlinear Optics、Advanced Fiber Laser Technologies

Two micrometer waveband has attracted much attention due to even-increasing data transmission and sensing needs. Waveguide-integrated photodetectors have been widely studied as one of the core devices in on-chip optical systems. However, bulk materials for photon-to-electron transition at 2 μm waveband such as HgCdTe or III–V compounds are incompatible with current integrated photonic platforms limited by lattice mismatch. As an alternative, van der Waals (vdW) materials, with exceptional optoelectronic characteristics, such as high mobility and strong light–matter interaction, can be freely integrated with arbitrary photonic platforms through vdW forces. In recent years, highly stable and narrow bandgap tellurium (Te) has been applied to construct mid-infrared detection with high responsivity and large bandwidth. However, the large shot noise of Te photodetectors results from a large dark current, limiting the detection of the weak light signals. Here, we introduce intrinsic n-type molybdenum ditelluride (MoTe 2 ) to construct a PN heterojunction with Te, thereby dark current can be suppressed as a result of the depletion layer at the interface, which is the first time to integrate Te-based heterojunction on commercial silicon photonic platform above communication waveband. As a result, the detectivity of our device reaches 2 × 10 9 cm·Hz 1/2 ·W –1 . Simultaneously, the obtained waveguide-integrated Te/MoTe 2 heterostructure photodetector possesses a responsivity of 94.16 mA...