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With the demand for communication, imaging, spectroscopy, and other applications, broadband detection has always been a particularly popular direction. However, the current photodetectors have the problems of relatively narrow response bands, a low sensitivity, a slow response speed, and complex manufacturing processes. In this article, the alloy material InBiSe3 is proposed to manufacture a wideband photodetector from visible to terahertz at room temperature. The noise equivalent power (NEP) of the detector is 1.37 × 10−10 W Hz−1/2 at 635 nm, 1.2 × 10−10 W Hz−1/2 at 808 nm, and 1.56 × 10−10 W Hz−1/2 at 980 nm. The device also exhibits a good response in the terahertz and millimeter-wave bands, with a NEP of 8.33 × 10−15 W Hz−1/2 at 0.023 THz, 7.03 × 10−14 W Hz−1/2 at 0.14 THz, 6.14 × 10−15 W Hz−1/2 at 0.171 THz, 1.91 × 10−14 W Hz−1/2 at 0.35 THz, and 4.04 × 10−14 W Hz−1/2 at 0.5 THz based on the electromagnetic induced potential wells effect. The response time is as fast as 10 µs. Our results demonstrate the promise of the InBiSe3 alloy for photoelectric applications and provide a method for the high performance of broadband photodetectors.

Current-controlled negative differential resistance (CC-NDR) phenomenon attracts a lot of interest for fabricating the access devices of nonvolatile memory based on crossbar array architectures. However, simple, bipolar, two-terminal commercial devices that exhibit CC-NDR are currently lacking because a number of critical characteristics needed to be met for such application. Here, we report the CC-NDR observed in Mn1.56Co0.96Ni0.48O4 (MCNO)- a small-polaron hopping material. Our experimental data and simulation reveal that the CC-NDR arises from self-heating effect due to the nature of strong electron-phonon coupling in small-polaron hopping system. The reported CC-NDR exhibits adjustable threshold voltage from 10-3 to 102 V, on-state current from 105 to 108 A/cm2 and off-state current is as low as ∼10 A/cm2 depending on device dimensions, thermal isolation condition, environmental temperature and activation energy of material. Uniquely, unlike in NbO2, Nb2O5, TiO2, TaOx et. al. materials, the CC-NDR in MCNO is more stable and reliable, because it does not undergo any electroforming process. These traits make MCNO a very potential candidate for CC-NDR devices.

Thin films of Mn1.95Co0.77Ni0.28O4are deposited on amorphous Al2O3 substrate by the magnetron sputtering method with the thickness of 6.5 μm. The effects of annealing treatment are studied on the film structural performance as well as the entropy of Mn-Co-Ni-O(MCNO) films by annealed at 400 ∘C, 500 ∘C, 600 ∘C, 700 ∘C, 800 ∘C respectively. It shows that the crystallinity of the thin film is the best annealed at 700 ∘C and the entropy is the largest because the number of different kinds of ions belonging to the same element equals with each other. After 800 ∘C annealing, the film resistivity is the minimal with the maximal entropy which means the highest stability.