Abstract-Ultrabroadband photosensitivity from visible to terahertz at room temperature

Dong Wu, Yongchang Ma, Yingying Niu, Qiaomei Liu, Tao Dong, Sijie Zhang, Jiasen Niu, Huibin Zhou, Jian Wei,Yingxin Wang, Ziran Zhao,  Nanlin Wang,

http://advances.sciencemag.org/content/4/8/eaao3057

Charge density wave (CDW) is one of the most fundamental quantum phenomena in solids. Different from ordinary metals in which only single-particle excitations exist, CDW also has collective excitations and can carry electric current in a collective fashion. Manipulating this collective condensation for applications has long been a goal in the condensed matter and materials community. We show that the CDW system of 1T-TaS2 is highly sensitive to light directly from visible down to terahertz, with current responsivities on the order of ~1 AW−1 at room temperature. Our findings open a new avenue for realizing uncooled, ultrabroadband, and sensitive photoelectronics continuously down to the terahertz spectral range.

Abstract-Uncooled EuSbTe3 photodetector highly sensitive from ultraviolet to terahertz frequencies

Biao Wang, Dong Wu, Hai Zhu, Huibin Zhou, Jian Wei, Nan Lin Wang, Jiasen Niu, Ping Zheng, Yingxin Wang, Yingying Niu, Yu Quan Su, Ziran Zhao

http://iopscience.iop.org/article/10.1088/2053-1583/aa939c/pdf

Light probe from Uv to THz is critical in photoelectronics and has great applications ranging from imaging, communication to medicine. However, the room temperature ultrabroadband photodetection across visible down to far-infrared is still challenging. The challenging arises mainly from the lack of suitable photoactive materials. Because that conventional semiconductors, such as silicon, have their photosensitive properties cut off by the bandgap and are transparent to spectrum at long-wavelength infrared side. Comparatively, the dielectrics with very narrow band-gap but maintain the semiconductor-like electrical conduction would have priorities for ultrabroadband photodetection. Here we report on EuSbTe3 is highly sensitive from ultraviolet directly to terahertz (THz) at room temperature. High photoresponsivities 1 ~ 8 A W-1 reached in our prototype EuSbTe3 detectors with low noise equivalent power (NEP) recorded, for instances ~ 150 pW  Hz-1/2 (at λ = 532 nm) and ~0.6 nW  Hz-1/2 (at λ = 118.8 µm) respectively. Our results demonstrate a promising system with direct photosensitivity extending well into THz regime at room temperature, shed new light on exploring more sophisticated multi-band photoelectronics