Enhanced performance of self-powered ultraviolet photodetectors coupled with the photovoltaic-pyroelectric effect based on ZnO/CuBO2 core-shell nanorod arrays

High‐Performance Ultraviolet Photodetectors Enabled by van der Waals Schottky Junction Based on TiO2 Nanorod Arrays/Au‐Modulated Ti3C2Tx MXene

“…The τ 1 and τ 2 are 0.11 and 1.05 s, respectively, and then the integrated decay time over Stage 3 is 1.3 s for FTA PDs. According to our previous study, [ 17 ] the effect of reverse burst current can be eliminated to shorten the rise/decay time by applying a definite reverse bias voltage and the built‐in potential will also be enhanced. However, in the FTA PDs, the reverse current is not reduced and meanwhile, the dark current gets increased after applying the reverse bias voltage in Figure S7a (Supporting Information), indicating that the Schottky barrier is so weak that applying a small bias voltage does not have a positive effect on blocking the reverse movement of the carriers.…”

“…To assess the performance of the FTTA PDs in the UV‐A light, the quantum efficiency (QE) test was carried out (Figure 5g). The responsivity and the apparent quantum efficiency (AQE, external quantum efficiency under a bias voltage) are also correlated as follows $${R_\lambda }\; = \;\frac{{q\lambda {\rm{AQE}}}}{{hc}}\;\; \times \;100\$, [ 17 ] where h is the Planck constant, c is the speed of light and λ is the wavelength of incident light. The highest responsivity is 1.95 × 10 5 mA W −1 (65,855% in AQE) under 370 nm illumination of 65.5 mW cm −2 at −1.5 V, exhibiting a robust detection capability of UV‐A light.…”

“…[ 50 ] Thus, the specific detectivity $$D_\lambda ^*$$ can be derived from the NEP as $$D_\lambda ^*\; = \;\frac{{{R_\lambda }}}{{\sqrt {2q{J_{{\rm{dark}}}}} }}$$. [ 17 ] Based on the R λ and J dark at −1.5 V, the $$D_\lambda ^*$$ is calculated to be 4.3 × 10 13 cm Hz 1/2 W −1 , implying the device has strong anti‐interference ability and weak light detection ability. Besides, the rise time can also be defined as 10% to 90% of the maximum value of the photogenerated current (decay time, 90% to 10% of the maximum value) to reflect the response speed.…”

“…[ 15,16 ] Moreover, the strong thermo‐electromotive force originating from the pyroelectric effect will cause a high instantaneous reverse current in the device based on a low‐dimensional structure especially when the UV light is switched off. [ 17 ] Therefore, suppressing the interfacial charge recombination and coordinating the hole‐trapping mechanism and the photovoltaic‐pyroelectric effect remain challenges to realize high‐performance TiO 2 NR‐based Schottky junction UV PDs.…”

Schiff-Base Chemistry-Coupled Catechol Oxidase-Like Nanozyme Reaction as a Universal Sensing Mode for Ultrasensitive Biosensing

“…The survey spectra of CHzyme in Figure C confirmed the presence of C, O, N, and Cu elements, while the survey spectra of His exhibited the absence of Cu element, demonstrating the successful combination of Cu and His. The binding energy (BE) at ∼934.48 and ∼954.39 eV of the Cu 2p spectrum in Figure D could be assigned to Cu 2p 3/2 and Cu 2p 1/2 of Cu­(II), respectively. − The peaks at ∼932.47 and ∼952.43 eV could belong to Cu 2p 3/2 of Cu­(I) and Cu 2p 1/2 of Cu­(II), respectively. , The peaks at ∼944.22 and ∼941.68 eV were connected with Cu­(II). , Additionally, the BE at ∼284.78, ∼285.80, and ∼287.97 eV in C 1s spectrum of His could be corresponded to CC/CC, CO, and CN, respectively. − Three peaks at ∼284.66, ∼285.60, and ∼287.46 eV in the C 1s spectrum of CHzyme could be assigned to CC/CC, CO, and CN, respectively (Figure E). − Meanwhile, two peaks at ∼530.67 and ∼531.42 eV in O 1s of His could be attributed to the CO bond and −OH. , Three peaks in O 1s of CHzyme at ∼530.35, ∼531.09, and ∼532.05 eV could be attributed to CuO, CO, and −OH, respectively, demonstrating the successful coordination between Cu and oxygen atoms (Figure F). − To demonstrate the coordination of Cu­(II) and N atoms in His, the N 1s spectrum of CHzyme was further researched (Figure G). Two peaks at ∼400.23 and ∼398.26 eV in N 1s of His could be attributed to amino groups and the CN bond, respectively. , The BE of ∼400.28 and ∼398.39 eV of CHzyme could be assigned to amino groups and the CN bond in His, respectively. , The peak at ∼399.20 eV exhibited the existing Cu–N bonds, confirming the successful coordination between Cu and N atom in CHzyme .…”