Wavelength-selective photodetectors responding to deep-ultraviolet (DUV) wavelengths (λ = 200−300 nm) are drawing significant interest in diverse sensing applications, ranging from micrometer biological molecules to massive military missiles. However, most DUV photodetectors developed thus far have suffered from long response times, low sensitivity, and high processing temperatures, impeding their practical use. Here, we report fast, high-responsivity, and general-substrate-compatible DUV photodetectors based on ultrathin (3−50 nm) amorphous gallium oxide (GaO X ) films grown by low-temperature (∼<250 °C) atomic layer deposition (ALD) for the first time. ALD-grown GaO X films on glass substrates display a typical amorphous nature, which is identified by electron beam diffraction and X-ray diffraction measurements, while their band gap is sharply featured at ∼4.8 eV. Metal−semiconductor−metal photodetectors (active area of 30 × 30 μm 2 ) using the 30-nm-thick GaO X films work reliably only for DUV wavelengths; the responsivity is maximized to 45.11 A/W at λ = 253 nm, which dropped off at λ ≈ 300 nm (i.e., a cutoff wavelength). The dark current measured at 10 V is as low as 200 pA and the signal-to-noise ratio reaches up to ∼10 4 , underpinning the pristine material quality of the ALD-grown GaO X films. In addition, the rise time (i.e., the time interval for photocurrent to increase from 10% to 90%) is as quick as 2.97 μs at λ = 266 nm. Such a reliable and fast photoresponse is achieved for even atomically thin (∼3 nm) devices. The substrate-compatible and low-temperature ALD growth permits the demonstration of flexible DUV photodetectors using amorphous GaO X films grown on polyimide substrates, suggesting their facile integration into other curved optoelectronic systems. We believe that photodetectors developed herein will provide an economically viable solution for high-performance DUV detection and create a variety of sensing applications.
We report the field-effect transistors using quasi-two-dimensional electron gas generated at an ultrathin (∼10 nm) AlO/TiO heterostructure interface grown via atomic layer deposition (ALD) on a SiO/Si substrate without using a single crystal substrate. The 2DEG at the AlO/TiO interface originates from oxygen vacancies generated at the surface of the TiO bottom layer during ALD of the AlO overlayer. High-density electrons (∼10 cm) are confined within a ∼2.2 nm distance from the AlO/TiO interface, resulting in a high on-current of ∼12 μA/μm. The ultrathin TiO bottom layer is easy to fully deplete, allowing an extremely low off-current, a high on/off current ratio over 10, and a low subthreshold swing of ∼100 mV/decade. Via the implementation of ALD, a mature thin-film process can facilitate mass production as well as three-dimensional integration of the devices.
BackgroundPostoperative sore throat (POST) is a complication that undermines patient satisfaction and increases discomfort in the postoperative period. The present study examined the effects of dexamethasone gargle and endotracheal tube cuff soaking on the incidence and severity of POST.MethodsNinety patients undergoing laparoscopic cholecystectomy were randomly allocated into three groups: 0.9% normal saline gargling and tube soaking (group C), 0.05% dexamethasone solution gargling and 0.9% normal saline tube soaking (group G), 0.9% normal saline gargling and 0.05% dexamethasone tube soaking (group S). The incidence and severity of POST were then assessed and recorded at 24 hours after surgery.ResultsThe total incidence of POST was significantly different among the groups (P < 0.05), and group S exhibited a significantly lower incidence of POST than group C (P < 0.0167). In addition, the POST intensity of group G and group S was less severe than those of group C (Both P < 0.0167).ConclusionsAmong patients undergoing laparoscopic cholecystectomy, those who gargled with 0.05% dexamethasone solution exhibited lower severity of POST than the control group, and those whose endotracheal tube cuff was soaked in the dexamethasone solution before intubation exhibited significantly lower incidence and severity of POST than the control group.
High-density polyethylene (HDPE) is a widely used organic polymer and an emerging pollutant, because it is very stable and nonbiodegradable. Several fungal species that produce delignifying enzymes are known to be promising degraders of recalcitrant polymers, but research on the decomposition of plastics is scarce. In this study, white rot fungus, Bjerkandera adusta TBB-03, was isolated and characterized for its ability to degrade HDPE under lignocellulose substrate treatment. Ash (Fraxinus rhynchophylla) wood chips were found to stimulate laccase production (activity was > 210 U/L after 10 days of cultivation), and subsequently used for HDPE degradation assay. After 90 days, cracks formed on the surface of HDPE samples treated with TBB-03 and ash wood chips in both liquid and solid states. Raman analysis showed that the amorphous structure of HDPE was degraded by enzymes produced by TBB-03. Overall, TBB-03 is a promising resource for the biodegradation of HDPE, and this work sheds light on further applications for fungus-based plastic degradation systems.
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