Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
1.
Angew Chem Int Ed Engl ; 62(42): e202311930, 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37665223

RESUMO

Cation-disordered Rocksalt oxides (DRXs) are a promising new class of cathode materials for Li-ion batteries due to their natural abundance, low cost and great electrochemical performance. High entropy strategy in Mn-based DRXs appears to be an effective strategy for improving the rate capability, but it suffers from challenges including capacity degradation. The present paper reports a new group of high entropy DRXs (HE DRX) based on Ni2+ -Nb5+ pair; the structural and chemical evolution upon cycling of DRXs with an increasing transition metal (TM) species are systematically investigated. An explanation is proposed for how the crystal field stability energy determines that HE DRX could exist in single Rocksalt solid solution structures. We further reveal that the charge compensation mechanism in HE DRX is the result of various TM synergistic effect. More importantly, through various in situ and ex situ techniques and theoretical calculation, the effective integration of more TM cation species within the HE DRX framework promotes better Li+ diffusion and improves lattice oxygen stability, consequently increasing capacity upon cycling.

2.
ACS Appl Mater Interfaces ; 15(25): 30152-30160, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37322853

RESUMO

The practical application of lithium-sulfur batteries (LSBs) is still hindered by several technical issues, including severe polysulfide shuttling and sluggish redox kinetics, which reduces the sulfur utilization and further results in low energy density. Herein, amorphous-crystalline heterostructured MnO2 (ACM) prepared through a simple calcination process was employed as the functional interlayer to play a double role as effective trapper and multifunctional electrocatalyst for LSBs. ACM not only combines the strong sulfur chemisorption of the amorphous MnO2 (AM) and fast Li+ transportation of the crystalline MnO2(CM) but also accelerates the interface charge transfer at the amorphous/crystalline interfaces. The LSBs with such unique interlayer exhibited an excellent rate performance of 1155.5 mAh·g-1 at 0.2 C and 692.9 mAh·g-1 at 3 C and a low decay rate of 0.071% per cycle over 500 cycles at 0.5 C. Even for a high sulfur loading of 5 mg·cm-2 at 0.1 C, a high capacity retention of 92.3% could also be achieved after 100 cycles. The concept of amorphous-crystalline heterostructures prepared by crystallization regulation might also be used for other electronic devices and catalyst designs.

3.
RSC Adv ; 12(51): 32825-32833, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36425168

RESUMO

Lithium-manganese-based cathode materials have attracted much attention due to its high specific capacity, but the low initial coulomb efficiency, poor rate performance and voltage attenuation during cycling limit its application. In this work, Li1.2Ni0.16Co0.08Mn0.56-x V x O2 samples (x = 0, 0.005, 0.01, 0.02, 0.05) were prepared using the sol-gel method, and the effects of different V5+ contents on the structure, valence state, and electrochemical performance of electrode materials were investigated. The results show that the introduction of high-valence V5+ in cathode materials can reduce partial Mn4+ to active Mn3+ ions for charge conservation, which not only improves the discharge capacity and coulomb efficiency of Li-rich manganese-based cathode materials, but also inhibits the voltage attenuation. The initial discharge capacity of the Li1.2Ni0.16Co0.08Mn0.55V0.01O2 is as high as 280.9 mA h g-1 with coulomb efficiency of 77.7% at 0.05C, which is much higher than that of the undoped pristine sample (236.6 mA h g-1 with coulomb efficiency of 74.0%). After 100 cycles at 0.1C, the capacity retention rate of Li1.2Ni0.16Co0.08Mn0.55V0.01O2 was 92.3% with the median voltage retention rate of 95.6%. This work provides a new idea for high performance of lithium-rich manganese-based cathode materials.

4.
ACS Appl Mater Interfaces ; 14(34): 38651-38659, 2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-35975901

RESUMO

Lithium-sulfur (Li-S) batteries (LSBs) have been considered one of the most potential candidates to substitute traditional Li-ion batteries (LIBs), owing to their high theoretical energy density and low cost. Nevertheless, the shuttle effect and the sluggish redox kinetics of lithium polysulfides (LiPSs) have long been obstacles to realizing stable LSBs with high reversible capacity. In this study, we proposed a metal-semiconductor (Mo and MoO2) heterostructure with the hollow microsphere morphology as an effective Mott-Schottky electrocatalyst to boost sulfur electrochemistry. The hollow structure can physically inhibit the shuttling of LiPSs and accommodate the volume fluctuation during cycling. More importantly, the built-in electric field at the heterointerfacial sites can effectively accelerate the reduction of LiPSs and oxidation of Li2S, thereby reaching a high sulfur utilization. With the assistance of the Mo/MoO2 catalyst, the cell exhibited prominent rate capability and stable long-term cycling performance, showing a high capacity of 630 mA h·g-1 at 4 C and a low decay of 0.073% at 1 C after 500 cycles. Even with high areal sulfur loading of 10.0 mg·cm-2, high capacity and good cycle stability were achieved at 0.2 C under lean electrolyte conditions (E/S ratio of 6 µL·mg-1).

5.
Genes (Basel) ; 13(4)2022 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-35456417

RESUMO

Family health history (FHH) can serve as an entry point for preventive medicine by providing risk estimations for many common health conditions. College is a critical time for young adults to begin to understand the value of FHH collection, and to establish healthy behaviors to prevent FHH-related diseases. This study seeks to develop an integrated theoretical framework to examine FHH collection behavior and associated factors among college students. A sample of 2670 college students with an average age of 21.1 years completed a web-based survey. Less than half (49.8%) reported actively seeking FHH information from their family members. Respondents' knowledge about FHH were generally low. Structural equation modeling findings suggested an adequate model fit between our survey data and the proposed integrated theoretical framework. Respondents who were members of racial/ethnic minority groups exhibited higher levels of anxiety and intention to obtain FHH information but had lower confidence in their ability to gather FHH information than non-Hispanic White respondents. Therefore, educational programs designed to enhance the level of young adults' FHH knowledge, efficacy, and behavior in FHH collection, and change subjective norms are critically needed in the future, especially for these who are members of racial/ethnic minority groups.


Assuntos
Etnicidade , Grupos Minoritários , Adulto , Saúde da Família , Humanos , Análise de Classes Latentes , Anamnese , Adulto Jovem
6.
Genes (Basel) ; 13(2)2022 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-35205283

RESUMO

The prevalence of autism spectrum disorders (ASD) in Taiwan has been increasing, and genetic testing for ASD has been available and provided to parents of children diagnosed with ASD in Taiwan. However, there is still limited understanding of Taiwanese parents' knowledge of and attitudes toward such testing. Therefore, the present study addressed this gap by assessing the attitudes toward as well as actual and perceived knowledge of ASD genetic testing among Taiwanese parents of children diagnosed with ASD. A sample of 443 parents of children with ASD recruited from 236 public schools in Taiwan completed a paper-and-pencil survey. Although parents generally held favorable attitudes toward ASD genetic testing, they had deficient knowledge of such test (with only a 31.4% average correct rate on the actual knowledge scale). Tailored health education materials should be developed to improve the knowledge of ASD genetic testing among parents with affected children in Taiwan.


Assuntos
Transtorno do Espectro Autista , Transtorno do Espectro Autista/diagnóstico , Transtorno do Espectro Autista/epidemiologia , Transtorno do Espectro Autista/genética , Criança , Testes Genéticos , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Pais , Taiwan/epidemiologia
7.
Am J Prev Med ; 61(3): 445-454, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34226092

RESUMO

CONTEXT: National efforts have advocated for the need to deliver family health history-based interventions to the lay public for more than a decade. Yet, the numbers, characteristics, and outcomes of such interventions are unknown. This first-of-its-kind systematic literature review examines the characteristics and effectiveness of the existing family health history-based interventions. EVIDENCE ACQUISITION: The research team systematically searched peer-reviewed articles published between January 2003 and July 2020 in MEDLINE, Embase, CINAHL, and Google Scholar. EVIDENCE SYNTHESIS: A total of 35 articles met the inclusion criteria. These studies assessed various behaviors, including family health history collection/communication with family members, family health history communication with healthcare providers, healthy diet adoption, physical activity level, uptake of medical screenings and genetic tests, and being proactive in healthcare matters. The average methodologic quality score of the studies was 9.9 (SD=1.6) of a theoretical range from 2 to 16. CONCLUSIONS: Many family health history-based interventions exist to examine a variety of behaviors. Yet, there is room for improvement in methodology because few studies used a randomized or quasi-experimental design. In addition, most included studies did not report objective or longer-term outcome data to examine the effectiveness of family health history-based interventions.


Assuntos
Exercício Físico , Pessoal de Saúde , Dieta Saudável , Humanos
8.
ACS Nano ; 15(7): 11491-11500, 2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34190550

RESUMO

The practical uses of lithium-sulfur batteries are greatly restricted by the sluggish reaction kinetics of lithium polysulfides (LiPSs), leading to low sulfur utilization and poor cyclic stability. Using the heterostructure catalysts is an effective way to solve the above problems, but how to further enhance the conversion efficiency and avoid the surface passivation by the insulative Li2S has not been well investigated. Herein, a heterostructure catalyst with rich heterointerfaces was prepared by modifying Mo2N microbelt with SnO2 nanodots. The formed rich interfaces with high accessibility act as the profitable nucleation sites guiding the Li2S 3D growth, which avoids the catalyst surface passivation and facilitates the LiPS conversion. The introduction of SnO2 nanodots also enhances the LiPS adsorption. Thus, the assembled battery with the above catalyst as the cathode additive shows a high capacity of 738.3 mAh g-1 after 550 cycles at 0.5 C with an ultralow capacity decay of 0.025% per cycle. Even with high sulfur loading of 9.0 mg cm-2, good cyclic stability is also achieved at 0.5 C with a low E/S ratio of 5 µL mgs-1. This work shows an effective way to enhance the LiPS conversion kinetics and guide Li2S deposition in Li-S batteries.

9.
Artigo em Inglês | MEDLINE | ID: mdl-33807035

RESUMO

Due to the increased prevalence of Autism Spectrum Disorder (ASD), more children with ASD may be referred for genetic testing. It is important to develop a tool to help parents consider the benefits and drawbacks of genetic testing for ASD before pursuing genetic testing for children with ASD. We developed the first theory-based survey-Perceptions of ASD Genetic Testing Survey (POAGTS), as a tool to assist healthcare providers to better understand parents' perceptions and concerns regarding ASD genetic testing. The psychometric properties of POAGTS were first pre-tested and then formally tested with 308 parents of children with ASD who had not decided whether to pursue genetic testing for their children diagnosed with ASD. Findings suggest that the eight scales of the POAGTS were psychometrically sound, and had acceptable data reliability and validity. Additional research with various samples, such as parents of children with ASD who belong to diverse racial/ethnic and socioeconomic groups, is warranted in the future to determine whether the POAGTS is applicable to these particular groups. Condensing and refining this tool to a shorter, more user-friendly version is also recommended for future research.


Assuntos
Transtorno do Espectro Autista , Transtorno do Espectro Autista/genética , Criança , Testes Genéticos , Humanos , Percepção , Psicometria , Reprodutibilidade dos Testes
10.
Nanoscale ; 13(9): 4921-4930, 2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33625417

RESUMO

Li-rich high-Mn oxides, xLi2MnO3·(1 - x)LiMO2 (x ≥ 0.5, M = Co, Ni, Mn…), have attracted extensive research interest due to their high specific capacity and low cost. However, slow Li2MnO3 activation and poor cycling stability have affected their electrochemical performance. Herein, to solve these problems, morphology regulation and LiAlF4 coating strategies have been synergistically applied to a Li-rich high-Mn material Li1.7Mn0.8Co0.1Ni0.1O2.7 (HM-811). This dual-strategy successfully promotes the activation process of the Li2MnO3 phase and thus improves the electrochemical performance of HM-811. Theoretical computation indicates that the LiAlF4 layer has a lower Li+ migration barrier than the HM-811 matrix, so it could boost the diffusion of Li+ ions and promote the activation of the Li2MnO3 phase. Benefiting from the morphology regulation and LiAlF4 coating, the HM-811 cathode shows a high initial charge capacity of >300 mA h g-1. In addition, the modified HM-811 could deliver superior electrochemical performance even at a low temperature of -20 °C. This work provides a new approach for developing high performance cathode materials for next-generation Li-ion batteries.

11.
Am J Prev Med ; 60(3): e159-e167, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33358550

RESUMO

Cancer is the second leading cause of death in the U.S. Utilizing family health history in cancer prevention holds promise in lessening the burden of cancer. Nevertheless, family health history is underutilized in public health and preventive medicine. Community health workers, also known as lay health educators, are ideal candidates to offer basic cancer family history-based education and services to the general public. The authors developed the first cancer family history-based genomics training program in cancer prevention tailored for community health workers. This paper details the development and pilot testing findings of the training. Specifically, a multidisciplinary research team of geneticists, genetic counselors, health educators, community health workers, and community health worker instructors developed a 7-module, 6-hour, bilingual (English and Spanish) cancer family history-based training focusing on cancer family history-based risk assessment, lifestyle recommendations, and genetic evaluation and testing. The curriculum was based on an integrated theoretical framework, the National Comprehensive Cancer Network guidelines, the community health worker core competencies, and the 4MAT instructional model. The Texas Department of State Health Services approved and certified the curriculum with 2 delivery formats: in-person/face-to-face workshops and online training. A total of 34 community health workers completed the pilot training in person (n=17) and online (n=17) in 2018 and 2019. Participating community health workers' knowledge, attitudes, self-efficacy, and intention in delivering basic cancer family history-based genomics education and services significantly increased on the immediate post-test measures compared with their pretest data. Positive ratings and feedback were also reported by the community health workers. Findings from this pilot study suggest that wider training is warranted for educating more community health workers in the U.S.


Assuntos
Agentes Comunitários de Saúde , Neoplasias , Genômica , Humanos , Anamnese , Neoplasias/genética , Neoplasias/prevenção & controle , Projetos Piloto , Texas
12.
Per Med ; 18(1): 55-66, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33332182

RESUMO

Background: Health educators (HEs), who are specialized in health education, can provide basic genomics education/services to the public. Such practice of HEs is unknown. We examined HEs' genomics knowledge and practice, intention, attitudes, self-efficacy and perceived barriers in providing basic genomics education/services. Materials & methods: Texas HEs (n = 662) were invited to complete the survey that was developed based on theoretical constructs (i.e., practice/behavior, intention, attitudes, self-efficacy, knowledge and perceived barriers) from various health behavior theories. Results: Among 182 HEs completed the survey, most had never/seldom provided basic genomics education/services. Participants' practice was positively associated with their intention in performing basic genomics education/services and previous genomics training. Intention to offer such education/services was positively related to HEs' self-efficacy and attitudes, which were correlated to previous genomics training. Conclusion: Texas HEs lacked basic genomics education/services practice. As previous genomics training was associated with HEs' practice, providing continuing education may enhance their practice.


Assuntos
Genômica/educação , Educadores em Saúde/organização & administração , Educação de Pacientes como Assunto/organização & administração , Adulto , Feminino , Educadores em Saúde/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Autoeficácia , Fatores Socioeconômicos , Texas
13.
J Genet Couns ; 30(2): 370-382, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32985757

RESUMO

The American Academy of Pediatrics, the American College of Medical Genetics and Genomics, and the American Academy of Neurology recommend genetic testing, as a genetic evaluation tool, for children diagnosed with autism spectrum disorders (ASD). Despite the potential benefits, the utilization of genetic testing is low. We proposed an integrated theoretical framework to examine parents' intention and associated psychosocial factors in pursuing genetic testing for their children with ASD. Recruiting primarily from the Interactive Autism Network, a nationwide sample of 411 parents of children with ASD who had never pursued genetic testing for their children completed our theory-based online survey. Data were analyzed using structural equation modeling. About half of the parents were willing to pursue genetic testing for their children with ASD. Findings of the structural equation modeling suggested a good model fit between our integrated theoretical framework and survey data. Parents' intention was significantly and positively associated with their attitudes toward genetic testing, subjective norm, and self-efficacy in having their children tested. This study serves as an initial window to understand parental intention to pursue genetic testing for their children with ASD. Our findings can help physicians and genetic counselors understand, educate, counsel, and support parents' decision-making about having their children with ASD genetically tested. Furthermore, our study can also assist physicians and genetic counselors in developing theory- and evidence-based patient education materials to enhance genetic testing knowledge among parents of children with ASD.


Assuntos
Transtorno do Espectro Autista , Transtorno do Espectro Autista/diagnóstico , Transtorno do Espectro Autista/genética , Criança , Testes Genéticos , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Pais , Inquéritos e Questionários
14.
Per Med ; 17(4): 295-306, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32618224

RESUMO

Background: There is a significant shortage of genomics training curricula targeting health education (HE) students. This study assessed the impact of an online theory-based genomics short course focusing on family health history (FHH) to undergraduate HE students. Materials & methods: Junior and senior HE students (n = 69) at a research-intensive university completed the course and took the pre- and post-course surveys. Results: Participants demonstrated positive improvements in their scores regarding FHH knowledge as well as attitudes, intention and confidence in adopting FHH-based genomics skills into future practice. They also showed satisfaction with the genomics course. Conclusion: Based on the initial success of the results, offering this genomics course to more HE students for further testing is recommended in the future.


Assuntos
Educação de Graduação em Medicina/métodos , Genômica/educação , Avaliação de Programas e Projetos de Saúde/métodos , Competência Clínica , Currículo , Feminino , Genômica/métodos , Educação em Saúde/métodos , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Estudantes , Inquéritos e Questionários , Adulto Jovem
15.
Dalton Trans ; 49(17): 5677-5683, 2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32292974

RESUMO

The "shuttle effect" of long-chain polysulfides and the low conductivity of elemental sulfur lead to the inferior cycling stability of lithium-sulfur batteries and imped their practical applications. Herein, Co3O4 nanoflakes with uniform macro pores distribution were synthesized via facile oil bath and calcination methods. Coupled with super P and coated on common polypropylene separators, they were expected to hinder the migration of lithium polysulfides (LiPSs) and accelerate the redox kinetics of polysulfides. Coin cells assembled with the Co3O4-super P interlayer exhibited a capacity of 760 mA h g-1 at 1 C, maintained 598 mA h g-1 after 350 cycles, and the decay rate of discharge capacity was only about 0.062% per cycle. Such high performance can be attributed to the synergistic effects between polar Co3O4 and conductive super P. The facile fabrication method and high performance make the Co3O4-super P interlayer a feasible material to apply in lithium-sulfur batteries.

16.
ACS Appl Mater Interfaces ; 12(10): 11579-11588, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32057232

RESUMO

Layered lithium-rich transition-metal oxides (LRMs) have been considered as the most promising next-generation cathode materials for lithium-ion batteries. However, capacity fading, poor rate performance, and large voltage decays during cycles hinder their commercial application. Herein, a spinel membrane (SM) was first in situ constructed on the surface of the octahedral single crystal Li1.22Mn0.55Ni0.115Co0.115O2 (O-LRM) to form the O-LRM@SM composite with superior structural stability. The synergetic effects between the single crystal and spinel membrane are the origins of the enhancement of performance. On the one hand, the single crystal avoids the generation of inactive Li2MnO3-like phase domains, which is the main reason for capacity fading. On the other hand, the spinel membrane not only prevents the side reactions between the electrolyte and cathode materials but also increases the diffusion kinetics of lithium ions and inhibits the phase transformation on the electrode surface. Based on the beneficial structure, the O-LRM@SM electrode delivers a high discharge specific capacity and energy density (245.6 mA h g-1 and 852.1 W h kg-1 at 0.5 C), low voltage decay (0.38 V for 200 cycle), excellent rate performance, and cycle stability.

17.
Artigo em Inglês | MEDLINE | ID: mdl-31940763

RESUMO

With the rapid growing rate of autism spectrum disorders (ASDs), prenatal genetic testing (PGT) has been offered to detect various genomic disorders, including ASD, in Taiwan. However, disparities exist in this area, as there is limited research on factors associated with PGT utilization and relevant decision-making that may guide the regulations and ethical guidelines for culturally appropriate PGT services in Taiwan. This study proposed a comprehensively integrated theoretical framework for examining the intention to undergo PGT to detect ASD susceptibility genes and subsequent abortion decision-making among Taiwanese mothers of children affected by ASD. Survey data from 333 mothers of children with ASD in 236 elementary schools with special education services in Taiwan were collected and analyzed using structural equation modeling. Approximately two-thirds of the participants (66.6%) would undergo PGT to detect ASD susceptibility genes; more than half (53.1%) would terminate the hypothetically ASD-affected pregnancy. Abortion intention was associated with age, religion, attitudes toward PGT for detecting ASD susceptibility genes, and willingness to undergo such PGT. This study explores the potential impacts of PGT on Taiwanese society, and the findings are applicable to countries heavily influenced by Chinese culture, areas with Asian immigrants, and Western countries with such PGT services and/or research available.


Assuntos
Aborto Induzido/psicologia , Povo Asiático/psicologia , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/psicologia , Predisposição Genética para Doença , Mães/psicologia , Teste Pré-Natal não Invasivo , Adulto , Tomada de Decisões , Feminino , Humanos , Recém-Nascido , Masculino , Gravidez , Inquéritos e Questionários , Taiwan
18.
RSC Adv ; 10(32): 19117-19123, 2020 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-35518286

RESUMO

Accurate and efficient screening of retired lithium-ion batteries from electric vehicles is crucial to guarantee reliable secondary applications such as in energy storage, electric bicycles, and smart grids. However, conventional electrochemical screening methods typically involve a charge/discharge process and usually take hours to measure critical parameters such as capacity, resistance, and voltage. To address this issue of low efficiency for battery screening, scanned X-ray Computed Tomography (CT) cross-sectional images in combination with a computational image recognition algorithm have been employed to explore the gradient screening of these retired batteries. Based on the Structural Similarity Index Measure (SSIM) algorithm with 2000 CT images per battery, the calculated CT scores are closely correlated with their internal resistance and capacity, indicating the feasibility of CT scores to sort retired batteries. We find out that when the CT scores are larger than 0.65, there is high potential for a secondary application. Therefore, this pioneering and non-destructive CT score method can reflect the internal electrochemical properties of these retired batteries, which could potentially expedite the battery reuse industry for a sustainable energy future.

19.
J Autism Dev Disord ; 49(12): 4821-4833, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31542846

RESUMO

This study examined the experiences of Autism Spectrum Disorder (ASD) genetic testing among parents of children with ASD. A nationwide sample of 552 parents of children with ASD completed an online survey. Nearly one-quarter (22.5%) of the parents reported that their affected children had undergone ASD genetic testing. The testing utilization was associated with awareness of ASD genetic testing and whether information was received from healthcare providers. Among parents whose children with ASD were tested, 37.6% had negative experiences, which mainly due to lack of perceived testing benefits to their affected children and unpleasant testing experiences with healthcare providers. To provide better healthcare services, it is critical to ensure parents understand the purposes, benefits, and results of ASD genetic testing.


Assuntos
Transtorno do Espectro Autista/epidemiologia , Transtorno do Espectro Autista/genética , Testes Genéticos/métodos , Pais , Inquéritos e Questionários , Adulto , Transtorno do Espectro Autista/diagnóstico , Conscientização , Criança , Pré-Escolar , Feminino , Testes Genéticos/tendências , Humanos , Masculino , Pessoa de Meia-Idade , Pais/psicologia , Estados Unidos/epidemiologia
20.
Nanomaterials (Basel) ; 9(9)2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31540315

RESUMO

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.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...