Two-dimensional (2D) tungsten disulfide (WS2) has inspired great efforts in optoelectronics, such as in solar cells, light-emitting diodes, and photodetectors. However, chemical vapor deposition (CVD) grown 2D WS2 domains with the coexistence of a discontinuous single layer and multilayers are still not suitable for the fabrication of photodetectors on a large scale. An emerging field in the integration of organic materials with 2D materials offers the advantages of molecular diversity and flexibility to provide an exciting aspect on high-performance device applications. Herein, we fabricated a photodetector based on a 2D-WS2/organic semiconductor materials (mixture of the (Poly-(N,N′-bis-4-butylphenyl-N,N′-bisphenyl) benzidine and Phenyl-C61-butyric acid methyl ester (Poly-TPD/PCBM)) heterojunction. The application of Poly-TPD/PCBM organic blend film enhanced light absorption, electrically connected the isolated WS2 domains, and promoted the separation of electron-hole pairs. The generated exciton could sufficiently diffuse to the interface of the WS2 and the organic blend layers for efficient charge separation, where Poly-TPD was favorable for hole carrier transport and PCBM for electron transport to their respective electrodes. We show that the photodetector exhibited high responsivity, detectivity, and an on/off ratio of 0.1 A/W, 1.1 × 1011 Jones, and 100, respectively. In addition, the photodetector showed a broad spectral response from 500 nm to 750 nm, with a peak external quantum efficiency (EQE) of 8%. Our work offers a facile solution-coating process combined with a CVD technique to prepare an inorganic/organic heterojunction photodetector with high performance on silicon substrate.
With the advent of the knowledge economy, universities have increasingly important roles in cities. However, some universities and cities are still fragmented, and popular science tourism is one way to solve this. The purposes and destinations of popular science tourism differ from those of traditional tourism. Consequently, their resources have a high development value for ecological and human resources. However, research on popular science tourism in China is still in its infancy. Here, we studied popular science tourism from a geographical perspective, selecting scale capacity, environmental level, resource level, location, and service conditions as factors to construct a judgment matrix to calculate the weights of indicators at various levels. Analytic hierarchy was used to build a popular science tourism evaluation system for Guangzhou University Town as a case study and the suitability of each tourist destination in the university town was evaluated. The results show that west Guangzhou University Town is more suitable for popular science tourism than the east, which possesses more value for popular science tourism development. Finally, we give recommendations for developing popular science tourism in Guangzhou University Town.
The Qinling Orogenic Belt is a typical composite continental orogenic belt in China. The Qinling Mountains is not only a natural demarcation that separates China into a southern part and a northern part, in terms of Qinling Orogenic Belt's geography, climate, organisms, and river systems, but also forms a cultural boundary between the Yellow River Civilization to the north and the Yangtze River Civilization to the south. The Xi'an Qinling Zhongnanshan World Geopark is situated in the major portion of the collision zone between the South China and North China plates, which is also a typical section of the Qinling Orogenic Belt. It has been the focus of great attention for its long history of geological evolution, intensive tectonism, various rock types, unique strata, frequent magmatism, and abundant geological heritage sites. This paper clarifies the regional geological background of the Qinling Zhongnanshan World Geopark in 3 aspects, that is, the regional geological setting, regional evolution, and regional strata. With an integrated analysis and classification, the paper describes the main features of geological relics and geological remains of scientific significance in the geopark, on the basis of an investigation and systematic analysis for the geological relic resources of the world geopark. Compared with the geosites in other world geoparks, the sites in the Zhongnanshan area are particularly distinctive, even unique.
Although some metadata standards such as LOM and Dublin Core are defined to offer the base and guarantee for education information sharing, there are still some shortcomings in e-Learning domain, the main one being their exclusive focus on property based specifications. Semantic web technologies allow us to enhance these specifications using classes of objects with common attributes. Another shortcoming of the standards is that they do not include any domain ontologies -which again can be specified building on semantic web formalisms. We try to explore the e-Learning repository and learner top layer ontology in our work. Based on the domain ontology, the algorithm of e-Learning resource semantic query is analyzed. Some SWRL rules are defined, so that new knowledge can be deducted from OWL knowledge database. The architecture of our learning repository is also described. Our practice indicate that some intelligent and personalization services in e-Learning can be achieved by using ontology and semantic web technology.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.