Search

Solar‐blind photodetectors have attracted extensive attention due to their advantages such as ultra‐low background noise and all‐weather. In this study, the planar Ti/Ga2O3/Au Schottky avalanche photodetector (APD) is fabricated based on β‐Ga2O3 epitaxial film on the sapphire substrate grown by metal–organic chemical vapor deposition. The Schottky APD exhibits a high responsivity of 9780.23 A W−1, an ultrahigh photo‐to‐dark current ratio of 1.88 × 107, an external quantum efficiency of 4.77 × 106%, a specific detectivity of 9.48 × 1014 Jones, with an ultrahigh gain of 1 × 106 under 254 nm light illumination at 60 V reverse bias, indicating high application potential for solar‐blind imaging. The superior photoresponse performances ascribe to the effective carrier avalanche multiplication, which contributes to the high photocurrent, and the high quality Schottky junction depletion, which leads to the low dark current. [ABSTRACT FROM AUTHOR]

The article reviewed migration, degradation, toxicity, and distribution of microplastics, which was focused on data enumeration of emission samples from countries around the North Pacific Ocean, South Atlantic Ocean, and Circumpolar oceans. Microplastic particles are easily absorbed by animals and spread to the whole food chain, and they have been confirmed to exist in the human body. It was well established that high abundance microplastics were trapped by ocean currents and accumulated in surface and sediment in convergence zones of the five subtropical gyres. While microplastic itself leaches out the toxin in the seawater, synergistic effects between microplastic and other pollutants increase microplastic toxicity for organisms. The monomers of 16 out of 55 plastic polymers were carcinogenic and mutagenic or toxic for reproduction. Additives used in the process are also dangerous polypropylene (PP), and polyethylene (PE) prefer to sorb persistent organic pollutants (POPs) and have an extremely slow rate of desorption, which form synergic effects and increase the toxicity of microplastics (MPs). For other plastic polymers, the sorption and desorption of pollutants by MPs depends on the concentration of POPs, so the toxicity of MPs varies with the content of pollutants. But for some types of MPs and POPs, the concentration of POPs controlled by microplastics also can decrease the lethal toxicity of POPs. Higher concentrations of MPs in the seawater cause larger MPs consumptions of marine organisms, especially in polar regains that have the highest MPs concentrations.

Tuning memory windows is vital for cross-bar memory architectures with low power and free cross-talk. Herein, we demonstrate a synergistic interface/electrode nanoengineering strategy to tune memory windows for low power operation and enhanced electrical readout in polymer devices; this approach is workable for most insulating or semiconducting polymeric mediums. Through customizing the resistivity of selectively reduced graphene oxide nanoelectrodes, an inherent sub μA current is recorded in the programming storage state. The nanocavity of the polymer interface can reduce the switching voltage due to local electric field enhancement, thus leading to tunable memory windows. By stacking a selector onto the memory, the vertical architecture features dynamic memory kinetics, enabling cross-talk-free readout by suppressing sneak leakage current paths. [ABSTRACT FROM AUTHOR]

Fabricating a heterojunction photodetector is efficient to take advantage of the built‐in electric field formed by heterojunction and thus improve the performance of photodetector. Herein, a CuZnS/Ga2O3 type‐II heterojunction photodetector is designed and constructed by chemical bath deposition for the first time. The photodetector exhibits super high rectifying characteristics (5.7 × 104 at ± 1 V), high responsivity (48.01 mA W−1 at 0 V), and detectivity (1.83 × 1012 Jones at 0 V), which are higher than most of the reported inorganic devices as far as the authors know. Benefiting from built‐in electric field constructed by the CuZnS/Ga2O3 type‐II heterojunction, the photo‐induced electron and hole pairs are quickly separated by the built‐in electric field between the Ga2O3 and the CuZnS interface. Therefore, the photodetector constructed by CuZnS/Ga2O3 type‐II heterojunction shows a prominent self‐powered performance. At zero bias, the photodetector shows a fast photoresponse (rise time τr = 70 ms, decay time τd = 10 ms). These data of performance are significantly excellent to most of the reported Ga2O3 heterojunction photodetectors. These performances strongly suggest that the CuZnS/Ga2O3 photodetector has great potential in ultra‐high performance self‐powered solar‐blind photodetector. [ABSTRACT FROM AUTHOR]

Mechanically exfoliated gallium oxide (Ga2O3) nano sheets based filed-effect-transistors (FETs) with Al2O3/Ga2O3, indium gallium zinc oxide (IGZO)/Ga2O3 n-n, and SnO/Ga2O3 p-n heterojunctions in the back-channel were fabricated. In contrast to that Al2O3/Ga2O3 heterojunction induces negative threshold voltage (${V} _{\text {TH}}$) shift, both IGZO/Ga2O3 n-n and SnO/Ga2O3 p-n heterojunctions shift ${V} _{\text {TH}}$ positively. The Ga2O3 FET with 12 nm p-type SnO realizes enhanced-mode operation with ${V} _{\text {TH}}$ of 5.3 V by significantly shifting ${V} _{\text {TH}}$ of 40.3 V, high on current density of 14.1mA/mm, and high electron mobility of 191 cm2V−1s−1, which is, to the best of our knowledge, the highest among the reported Ga2O3 FETs measured at room temperature. [ABSTRACT FROM AUTHOR]

Thin-film Schottky barrier diodes (SBDs) based on amorphous oxide semiconductors play an important role in flexible and wearable electronics. In this work, thin-film SBDs based on indium–gallium–zinc oxide (InGaZnO or IGZO) were fabricated with sputtered PdOx/Pd top Schottky contact and low-temperature (100 °C) annealing in air atmosphere. PdOx produces an oxygen-rich stoichiometry in the Schottky interface, resulting in high-quality contact with rather low interface trap state density of $2.6\times 10^{17}$ cm−3 and extremely low barrier inhomogeneity of 0.01 eV. As a result, high-performance IGZO SBDs were achieved with high ON/ OFF ratio of $3\times 10^{7}$ , near–unity ideality factor of 1.04, barrier height of 0.85 eV, high ON-current density of 2.5 $\text{A}\cdot $ cm−2 at 1 V, and high reverse breakdown voltage of ~12 V. [ABSTRACT FROM AUTHOR]

Low‐dimensional MXene materials including MXene quantum dots (MQDs) and nanosheets have attracted extensive attention owing to their unique structures and novel properties, but their most attractive features are still less explored than expected. A systematic study of the memory effects of MQD‐based electronics is reported. Monodisperse MQDs are prepared by using a one‐step facile hydrothermal synthetic method. By varying the MQD content in polyvinylpyrrolidone (PVP) hybrid composite films, the electrical conductance of an indium tin oxide (ITO)/MQD‐PVP/gold (Au) sandwich structure can be tuned precisely from insulator behavior to irreversible resistive switching, reversible resistive switching, and conductor behavior. These irreversible and reversible resistive switches are capable of exhibiting write‐once‐read‐many times (WORM) and flash memory effects, respectively. Both types of devices operate stably under retention testing, with a high on/off current ratio up to 100. The tunable memory and transient features of these hybrid films are likely due to MQD charge trapping due to their quantum confinement and dissolvability of memristive components. The results suggest that MXene nanomaterials are promising as resistive switching trigger for emerging nonvolatile memories for data storage, specially data storage security. [ABSTRACT FROM AUTHOR]