Detection in multiple infrared (IR) regions spanning from short- and mid- to long-wave IR plays an important role in diverse fields from scientific research to wide-ranging technological applications, including target identification, imaging, remote monitoring, and gas sensing. Currently, state-of-the-art IR photodetectors are mainly dominated by conventional narrow bandgap semiconductors including In1-xGaxAs, InSb, and Hg1-xCdxTe, operating in short-wave IR (SWIR, 1-3 µm), mid-wave IR (MWIR, 3-6 µm), and long-wave IR (LWIR, 6-15 µm) spectral bands, respectively.
a, Schematic illustration of a graphene/1Tʹ-MoTe₂/Si Schottky junction device. b,Time-dependent photoresponse properties to pulsed light illumination in a broad spectral band. c, Comparison of the room-temperature specific detectivity of the Gr/1Tʹ-MoTe₂/Si Schottky junction device with other devices. Credit: Di Wu, Chenguang Guo, Longhui Zeng, Xiaoyan Ren, Zhifeng Shi, Long Wen, Qin Chen, Meng Zhang, Xin Jian Li, Chong-Xin Shan, and Jiansheng Jie Detection in multiple infrared (IR) regions spanning from short- and mid- to long-wave IR plays an important role in diverse fields from scientific research to wide-ranging technological applications, including target identification, imaging, remote monitoring, and gas sensing. Currently, state-of-the-art IR photodetectors are mainly dominated by conventional narrow bandgap semiconductors including In 1-x Ga x As, InSb, and Hg 1-x Cd x Te, operating in short-wave IR (SWIR, 1-3 µm), mid-wave IR (MWIR, 3-6 µm), and long-wave IR (LWIR, 6-15 µm) spectral bands, respectively. Notably, these photodetectors not only rely on high-temperature growth process of raw materials and complex processing technique, but also suffer from the cryogenic cooling conditions with time-consuming and high power consumption. Moreover, there are several remaining technological challenges, such as poor complementary metal-oxide-semiconductor (CMOS) compatibility, bulky module size and low efficiency, which severely restrict the wider application of these detectors. In a new paper published in Light Science & Application, Professors Di Wu and Xinjian Li from Zhengzhou University, Dr. Longhui Zeng from the University of California-San Diego, and Prof. Jiansheng Jie from Soochow University have demonstrated a facile thermal-assisted tellurization route for the van der Waals (vdW) growth of wafer-scale phase-controlled 2D MoTe 2 layers. The type-II Weyl semimetal 1T′-MoTe 2 layers were directly deposited on…