Vertical Barrier Heterostructures for Reliable, Robust, and High‐Performance Ultraviolet Detection

Abstract

Photodetectors based on low‐dimensional materials usually suffer from serious optical power‐dependent photoresponse and low reliability, particularly in the ultraviolet regime. The barrier photodetector is an effective and reliable strategy where the barrier layer can block the low‐energy charge carriers while allowing for a flow of the high‐energy photocarriers. Here, vertical barrier heterostructure photodetectors (VBHPs), consisting of a graphene bottom electrode, a MoS2 light absorber, and an h‐BN energy barrier, for reliable, robust, and high‐performance ultraviolet detection are reported. The asymmetric barrier distribution in the conduction/valence band at the MoS2/h‐BN interface results in an ultralow noise current of 1.69 × 10‐15 A Hz‐1/2 at room temperature, stable photo on/off states exceeding 104 cycles at 300 K and 400 K, a light power‐independent high responsivity of 416.2 mA W‐1 at 360 nm, a high photo on–off ratio of 1.2 × 105 at 360 nm, high measured detectivities (3.2 × 1010 Jones at 266 nm and 9.9 × 1010 Jones at 360 nm), and wide linear dynamic ranges. The VBHPs show a high potential for new‐type reliable ultraviolet detection.

Real-Time Ultraviolet Monitoring System with Low-Temperature Solution-Processed High-Transparent p–n Junction Photodiode with a Fast Responsive and High Rectification Ratio

“…Additionally, this curve is fitted using the power law formula I ph ∼ P α , α = 0.92, where coefficient α determines the response of the photocurrent to light intensity. The nonunity coefficient (0.5 < α < 1) indicates a complex process involving carrier generation, recombination, and trapping within the semiconductor. , Moreover, the coefficient, which is close to unity at 0.92, suggests that almost negligible loss in photocarrier transport occurs due to effective low-energy charge carrier blocking due to the energy barrier of the PTAA/ZnO structure …”

“…37,38 Moreover, the coefficient, which is close to unity at 0.92, suggests that almost negligible loss in photocarrier transport occurs due to effective low-energy charge carrier blocking due to the energy barrier of the PTAA/ZnO structure. 10 . 39,40 Here, h, c, e, and λ represent the Planck constant, the speed of light, the elementary charge of an electron, and the wavelength of the light, respectively.…”

Vertical Van Der Waals Epitaxy of p‐MoxRe1‐Xs2 on GaN for Ultrahigh Detectivity Uv–vis–NIR Photodetector

“…Furthermore, as illustrated in Figure 5f,g, the fully vertical p‐Mo x Re 1‐ x S 2 /GaN photodetector showcases the most superior performance when exposed to 365 nm light irradiation. From similar devices in the benchmark, [ 21,25,71–97 ] it exhibits an impressively low NEP value of 7.26 × 10 −18 W/Hz 1/2 , indicating excellent sensitivity, and achieves the highest D * value of 6.13 × 10 14 Jones, reflecting its outstanding detectivity. The superiority of vertical devices over others primarily lies in the fact that, compared to lateral devices, the current flows longitudinally in vertical devices, allowing for a larger conduction area capable of withstanding higher power densities.…”

Nonvolatile Memristive Materials and Physical Modeling for In‐Memory and In‐Sensor Computing

“…Nevertheless, various connected sensors or single self-adaptive sensor types process the sensory data directly, which integrate computing operations and sensing functions, in an in-sensor computation architecture. [44][45][46][47] In this review, we provide an overview of the switching signature and system character utilized in three typical MM systems, along with a combined application survey for developing in-memory computing, as well as in-sensor computation (Figure 2). We also disclose an outlook on the challenge and opportunities.…”