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Ultrafast 0D/1D ZnO/CuO photodetector in nanosecond scale by engineering the type-II heterostructure
Zero-dimensional/one-dimensional (0D/1D) heterojunctions have excellent potential in the field of optoelectronic devices due to the synergy effect of different dimensions. Most reported 0D/1D heterojunction photodetectors only focus on optimizing the separation efficiency of photogenerated carriers at the interface. However, the carriers within the quantum dots (QDs) cannot be transferred to the electrodes, resulting in recombination of photogenerated carriers separated at the interface. Therefore, the response speed of most 0D/1D heterojunction photodetectors is still limited to the order of seconds (s) and milliseconds (ms). In our work, we demonstrate a nanosecond (ns) scale ZnO/CuO heterojunction photodetector with efficient photoelectric conversion by engineering the type-II 0D/1D heterojunction interface. Herein, the surface defect states of ZnO QDs are deliberately introduced as “electrons storage pool” to suppress carrier recombination and further promote separation, which has been confirmed by photoluminescence (PL) and time-resolved photoluminescence (TRPL). As a result, the photodetector exhibited excellent performance with ultrafast response speed of 20 ns, responsivity of 213 A/W, and detectivity of 2.95 × 1011 Jones, respectively. This defect related interface engineering provides a feasible strategy for the development of high-performance 0D/1D heterojunction photodetectors.
Multi-band nonreciprocal thermal radiation based on Weyl semimetals with epsilon-near-zero multilayers
Although various nonreciprocal thermal emitters have been suggested to break the balance between absorption and emission, few structures can achieve strong nonreciprocity in more than three bands. To break this constraint, we propose a nonreciprocal thermal emitter device based on GaN/AIN/SiC/Weyl semimetal (WSM), which is capable of three discrete pairs of near-perfect absorption and emission, leading to perfect hexa-band strong nonreciprocal radiation. The enhanced nonreciprocal thermal radiation is attributed to the field enhancement of epsilon-near-zero layer and nonreciprocal guided resonances excited in the WSM film. By studying the magnetic field distribution, the physical mechanism of multi-band nonreciprocal thermal radiation is revealed, which can be verified by the impedance matching theory. Furthermore, the dependence of the structure dimensions and the axial vector b of the Weyl semimetal on the performance of the nonreciprocal radiation is investigated in detail. We believe that this work can provide an approach to the development of energy conversion devices and frequency selective detectors.
Characterizing self-heating dynamics using cyclostationary measurements
Self-heating in surround gate (e.g., nanosheet, nanowire, and FinFET) transistors degrades their on-current performance and reduces their lifetime. If a transistor heats/cools with time constants much shorter than the inverse of the operating frequency, predictable, frequency-independent performance is expected; if not, the operating frequency must be optimized for the highest performance. Typically, time constants are measured by expensive, ultra-fast instruments with high temporal resolution. Instead, here, we demonstrate an alternate, inexpensive, cyclostationary measurement technique to characterize self-heating (and cooling) with sub-microsecond resolution. The results are independently confirmed by direct imaging of the transient heating/cooling of the channel temperature by the thermoreflectance method. Routine use of the proposed technique will help improve the design of the surrounding gate transistors and shorten their design cycle.
Dual-branch image projection network for geographic atrophy segmentation in retinal OCT images
Plasmodium falciparum Pfs47 haplotype compatibility to Anopheles gambiae in Kisumu, a malaria-endemic region of Kenya
Abstract Insecticide resistance and outdoor transmission have reduced the effectiveness of existing malaria transmission prevention strategies. As a result, targeted approaches to support continuing malaria control, such as transmission-blocking vaccines, are required. Cross-sectional mass blood screening in children between 5 and 15 years was conducted in Chulaimbo, Kisumu, during the dry and wet seasons in 2018 and 2019. Plasmodium falciparum gametocyte carriers were identified by Microscopy. Subsequently, carriers were used to feed colony bred Anopheles gambiae females in serum replacement and whole blood membrane feeding experiments. The infection prevalence was 19.7% (95% Cl 0.003–0.007) with 95% of the infections being caused by P. falciparum . Of all confirmed P. falciparum infections, 16.9% were gametocytes. Thirty-seven paired experiments showed infection rates of 0.9% and 0.5% in the serum replacement and whole blood experiments, respectively, with no significant difference (P = 0.738). Six Pfs47 haplotypes were identified from 24 sequenced infectious blood samples: Hap_1 (E27D and L240I), Hap_2 (S98T); Hap_3 (E27D); Hap_4 (L240I); Hap_5 (E188D); and Hap_6 without mutations. Haplotype 4 had the highest frequency of 29.2% followed by Hap_3 and Hap_6 at 20.8% each then Hap_1 with a frequency of 16.7%, whereas Hap_5 and Hap_2 had frequencies of 8.3% and 4.2% respectively. Varying frequencies of Pfs47 haplotypes observed from genetically heterogeneous parasite populations in endemic regions illuminates vector compatibility to refracting P. falciparum using the hypothesized lock and key analogy. This acts as a bottleneck that increases the frequency of P. falciparum haplotypes that escape elimination by vector immune responses. The interaction can be used as a potential target for transmission blocking through a refractory host.
Risk factors for pterygium recurrence based on a retrospective study of 196 patients
Association of cholecystectomy with short-term and long-term risks of depression and suicide
Pathophysiological link between carotid atherosclerosis and cerebral white matter lesions
Mitigating doxorubicin-induced hepatotoxicity in male rats: The role of aerobic interval training and curcumin supplementation in reducing oxidative stress, endoplasmic reticulum stress and apoptosis
Characterization of the electronic structure and fate of doubly ionized carbon diselenide
Abstract Single photon double ionization of carbon diselenide ( $${\hbox {CSe}}_{2}$$ ) has been investigated by means of multi-particle coincidence techniques. The interpretation of the experimental spectra is helped by post-Hartree-Fock computations at the Coupled Clusters and Multi-Reference Configuration-Interaction levels to determine the energetics and electronic state potentials of $$\hbox {CSe}_2^{2+}$$ and its fragments. The lowest experimental double ionization energy of $${\hbox {CSe}}_{2}$$ has been found to be 24.68 ± 0.20 eV, reflecting the $$\hbox { X} ^3\Sigma ^-_g$$ ground state, and is in agreement with the theoretical vertical double ionization energy of 24.41 eV. Several fragmentation channels are reported including experimental appearance energies and kinetic energy releases in comparison to theoretical results on their characteristics. In particular, we identify several purely repulsive, Coulomb explosion fragmentation channels.