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1.
Am J Occup Ther ; 78(2)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38393990

RESUMO

IMPORTANCE: Although cross-sectional studies have reported the relationships among performance of activities of daily living (ADLs), income satisfaction, and health satisfaction, longitudinal associations in stroke survivors remain unclear. OBJECTIVE: To examine the effects of ADL function and income satisfaction on health satisfaction over time in stroke survivors. DESIGN: Retrospective longitudinal study designs with latent growth curve models (LGMs) to control for time-varying and time-invariant covariates. SETTING: Community. PARTICIPANTS: A total of 198 stroke survivors. OUTCOMES AND MEASURES: Self-reported ADL performance, income satisfaction, and health satisfaction. RESULTS: The average age of participants was 70.68 yr (SD = 8.09; 107 men, 91 women). Each LGM showed that an increase in ADL score (standardized ß = 0.116∼0.296, all ps < .05) and income satisfaction (standardized ß = 0.513∼0.726, all ps < .001) positively predicted health satisfaction over time, even after controlling for time-varying annual income, demographics, and behavioral characteristics. The fit results of all LGMs were within the acceptable range: χ2(47) = 66.378, p = .0327; χ2(47) = 57.742, p = .1355; root-mean-square error of approximation, <0.08; comparative fit index and Tucker-Lewis index, >0.90; standardized root-mean-square residual, <0.05. CONCLUSIONS AND RELEVANCE: Because ADLs are significant modifiable health satisfaction factors, occupational therapy practitioners would need to focus more closely on ADL training in clinical settings. Furthermore, referring those clients to appropriate vocational rehabilitation to improve their income satisfaction would be necessary. Plain-Language Summary: This study recognizes the unique challenges and opportunities that arise when stroke survivors are preparing to return to their communities by emphasizing the significance of ADL training and income satisfaction during this stage of recovery. The study suggests that the therapeutic use of ADL training and income satisfaction could increase health satisfaction for stroke survivors. Therefore, comprehensive ADL training, as an occupational therapy intervention, could be crucial for stroke survivors who are preparing to return to their community from a clinical setting. Furthermore, connecting with vocational rehabilitation could also be important for improving income satisfaction for stroke survivors who are preparing to return to a community.


Assuntos
Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Masculino , Humanos , Feminino , Atividades Cotidianas , Estudos Transversais , Estudos Retrospectivos , Estudos Longitudinais , Estado Funcional , Sobreviventes , Satisfação Pessoal
2.
Int J Aging Hum Dev ; 97(4): 496-512, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-36560911

RESUMO

This study investigates the psychometric properties of the Meaningful Activity Participation Assessment-Meaning (MAPA-M) scale using the Rasch measurement model. For the psychometric properties of MAPA-M, principal component analysis, Rasch analysis, and differential item functioning analysis were conducted. Participants in this study were 480 older adults from the USC Well Elderly 2 study, recruited from 21 locations in the Los Angeles metropolitan area. There were eight items with DIF, but they were accepted because they assumed unidimensionality and showed good person invariance. The 25 items assuming unidimensionality of MAPA-M had values between 0.6 and 1.4 in infit and Outfit MnSq, and all ZSTD values were less than 2.0. The 25 items demonstrated a conceptual item-difficulty hierarchy. The person strata value was 2.68, which is equivalent to a reliability index value of .76. The findings indicate that the revised scale can accurately and reliably measure meaningful activities by older adults.


Assuntos
Psicometria , Humanos , Idoso , Reprodutibilidade dos Testes , Inquéritos e Questionários
3.
J Aging Phys Act ; 30(5): 770-777, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34879330

RESUMO

This study examined the association between achieving the recommended physical activity level and quality of life after controlling for depression. Health information from adults aged 65 years and older, who had participated in the seventh 2018 Korea National Health and Nutrition Examination Survey, was used. Five covariate adjustment models were used to derive robust estimates of the association between physical activity practice levels, depression, and older adults' quality of life. A total of 1,336 older adults was extracted from the seventh 2018 Korea National Health and Nutrition Examination Survey, and 31% of the older adults achieved the recommended physical activity level, whereas 69% did not. We found that the achievement of physical activity practice levels is significantly associated with the quality of life of the older adults (ß = 0.024-0.031, all p < .05). Our results could be used for advocating for welfare policy changes that promote physical activity to prepare for the upcoming super-aging society.


Assuntos
Vida Independente , Qualidade de Vida , Idoso , Estudos Transversais , Depressão , Exercício Físico , Humanos , Inquéritos Nutricionais , Pontuação de Propensão
4.
Biochem Biophys Res Commun ; 515(1): 183-189, 2019 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-31133378

RESUMO

Heterotypic cell-cell interaction between cancer cells and pancreatic stellate cells (PSCs) within tumor microenvironment is considered as a key mechanism for epithelial-mesenchymal transition (EMT) that triggers disease progression and chemoresistance in pancreatic ductal adenocarcinoma (PDAC). Hence, PSCs should be incorporated into in vitro co-culture models to maximize clinical relevance of data obtained using these models. In this study, we developed hetero-type spheroids of pancreatic cancer cells (ductal carcinoma cells PANC-1 and primacy sarcomatoid adenocarcinoma 36473 cells) and PSCs. Effect of PSC co-culture on the formation and growth of multicellular spheroids was cell-line dependent in that growth stimulation effect appeared in PANC-1/PSC spheroids, but not in 36473/PSC spheroids. Spatial distribution of PSCs within spheroids was also cell-line dependent. It was either confined to the center region (PANC-1) or evenly distributed (36473). Changes in expression levels of E-cadherin and vimentin revealed EMT induction in PANC-1/PSC hetero-type spheroids, but not in 36473/PSC spheroids. Gemcitabine sensitivity was increased partially by PSC co-culture. However, PSCs showed relative resistance to gemcitabine compared to PANC-1 cells in PANC-1/PSC spheroids. Overall, our hetero-type spheroid model can be used to study cancer-stroma interaction and their mechanism and evaluate anticancer drug activity. We demonstrated that stromal effect by PSC co-culture might be cellular context dependent with regard to growth stimulation and EMT induction. Hence, anti-stromal therapy should take these differences into consideration.


Assuntos
Carcinoma Ductal Pancreático/metabolismo , Comunicação Celular , Neoplasias Pancreáticas/metabolismo , Células Estreladas do Pâncreas/metabolismo , Antimetabólitos Antineoplásicos/farmacologia , Caderinas/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Humanos , Neoplasias Pancreáticas/patologia , Células Estreladas do Pâncreas/citologia , Esferoides Celulares/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacos , Vimentina/metabolismo , Gencitabina
5.
J Nanosci Nanotechnol ; 19(2): 1048-1051, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30360198

RESUMO

We studied the optical sensing properties of ZnO nanoparticles prepared by spray pyrolysis. To investigate their optical sensing performance, we incubated peptides on ZnO nanoparticles. The photoluminescence (PL) peak intensity of peptides on the ZnO nanoparticles was higher than that of peptides on the ZnO film or on the glass plate. This observed PL enhancement is attributed to the optical confinement of ZnO nanoparticles. The low-temperature spectra displayed a strong exciton emission peak with multiple sidebands, attributed to the bound exciton and its longitudinal optical phonon sidebands. The strong exciton emission is thought to be the combined effect of optical confinement due to the nanoparticle geometry, reduction of defect emission by thermal annealing, and reduction of non-radiative relaxation at low temperatures.

6.
J Nanosci Nanotechnol ; 18(9): 5970-5975, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29677726

RESUMO

Color changes controlled by electronic energies have been studied for many years in order to fabricate energy-efficient smart windows. Reduction and oxidization of nickel oxide under the appropriate voltage can change the color of a window. For a superior nickel oxide (NiO) electrochromic device (ECD), it is important to control the chemical and physical characteristics of the surface. In this study, we applied polystyrene bead templates to nickel oxide films to fabricate a honeycomb-structured electrochromic (EC) layer. We synthesized uniform polystyrene beads using the chemical wet method and placed them on substrates to create honeycomb-structured NiO films. Then, the EC characteristics of the nickel oxide films with a honeycomb structure were evaluated with UV-Visible and cyclic voltammetry. FE-SEM and AFM were used to measure the morphologies of the nanostructures and the efficiencies of the redox reactions related to the specific surface area.

7.
J Nanosci Nanotechnol ; 14(12): 9489-92, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25971088

RESUMO

To date, organic photovoltaic devices (OPVs) have obtained relatively low power conversion efficiency, mostly because of the low charge carrier mobility of the polymers to be used. This limits the optimal film thickness for efficient absorption of the solar spectrum. The capability of efficient charge carrier collections is a main factor for utilizing thick OPVs, consequently enhancing the power conversion efficiency. In this report, we demonstrate a facile approach for enhancing the hole carrier collection by possibly shortening the hole collection path via structuring poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PEDOT: PSS), which is widely used as a hole collecting intermediate layer in OPVs. For structuring the PEDOT: PSS, the nanosphere lithographic method was used. Furthermore, the effects of the structuring of PEDOT: PSS on optical properties were also investigated.


Assuntos
Poliestirenos/química , Tiofenos/química , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura
8.
PLoS One ; 19(5): e0301035, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38748645

RESUMO

The study aimed to investigate the survival rate of patients with dementia according to their level of physical activity and body mass index (BMI). A total of 5,789 patients with dementia were retrieved from the 2009-2015 National Health Insurance Sharing Service databases. Survival analysis was used to calculate the hazard ratio (HR) for physical activity and BMI. The study sample primarily comprised older adults (65-84 years old, 83.81%) and female (n = 3,865, 66.76%). Participants who engaged in physical activity had a lower mortality risk (HR = 0.91, p = 0.02). Compared to the underweight group, patients with dementia who had normal weight (HR = 0.86, p = 0.01), obesity (HR = 0.85, p = 0.03) and more than severe obesity (HR = 0.72, p = 0.02) demonstrated a lower mortality risk. This study emphasizes the significance of avoiding underweight and engaging in physical activity to reducing mortality risk in patients with dementia, highlighting the necessity for effective interventions.


Assuntos
Índice de Massa Corporal , Demência , Exercício Físico , Humanos , Feminino , Idoso , Demência/mortalidade , Demência/epidemiologia , Masculino , Idoso de 80 Anos ou mais , Programas Nacionais de Saúde , Bases de Dados Factuais , Obesidade/mortalidade , Magreza/mortalidade
9.
PLoS One ; 19(7): e0306907, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38980869

RESUMO

With the increasing number of older adults, research on cognitive function has expanded. However, studies examining the mediating effect of depression on the association between complex factors and cognitive function in older adults are still insufficient. Additionally, there is a lack of studies that have investigated these relationships by integrating multiple factors related to the cognitive function of older adults. Therefore, our study investigated the association between the number of family members, self-rated health, depression, and cognitive function in community-dwelling older adults and highlighted the mediating role of depression in these relationships. We used data from 218 older adults aged over 65 collected in a previous study. The independent variables were the number of family members and self-rated health, and the dependent variable was cognitive function measured by the cognitive impairment screening test (CIST). The mediation variable was depression measured by the Patient Health Questionnaire-9 (PHQ-9). Structural equation modeling was used to examine the association between the independent, dependent, and mediation variable. The mean ages of the participants were 81.71 (standard deviation [SD] = 6.00) years, with 198 females (90.83%) and 20 males (9.17%). The structural equation model demonstrated a good model fit (chi-square value = 33.375; degrees of freedom = 24; p-value = 0.0964; RMSEA = 0.042; CFI = 0.970; TLI = 0.956; SRMR = 0.042). Self-rated health and the number of family members were not directly associated with cognitive function; however, depression had significant indirect effects (self-rated health to cognitive function: coefficient = -0.023, p-value = 0.017; number of family members and cognitive function: coefficient = 0.012, p-value = 0.030). Our findings indicated that depression plays a crucial mediating role between self-rated health, number of family members, and cognitive function. The results highlight the need for comprehensive strategies for mental health care to support cognitive health in older adults.


Assuntos
Cognição , Depressão , Família , Vida Independente , Humanos , Masculino , Feminino , Idoso , Depressão/epidemiologia , Depressão/psicologia , Cognição/fisiologia , Vida Independente/psicologia , Idoso de 80 Anos ou mais , Família/psicologia , Nível de Saúde , Autorrelato , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/psicologia
10.
OTJR (Thorofare N J) ; 43(2): 202-210, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36377234

RESUMO

Older adults gradually decrease their independence with activities of daily living (ADL) due to aging. The coronavirus disease-19 (COVID-19), the recent pandemic, can accelerate the decline in functions, such as ADL. This study aimed to examine whether there is an association between positive COVID-19 results and decreased independence with ADL in older adults. Data for a total of 3,118 older adults were extracted from the 2020 National Health and Aging Trends Study-COVID-19. A total of 71 (2.29%) participants presented with positive COVID-19 tests. There was a significant association between a positive COVID-19 result and decreased independence with ADL (relative risk [RR] = 1.47, 95% confidence interval [CI] = [1.11, 1.96], p = .0079). The study findings revealed that COVID-19 survivors had a high risk of decreased independence with ADL. These findings indicate that COVID-19 survivors have residual functional deficits and would need comprehensive health care services.


Assuntos
Atividades Cotidianas , COVID-19 , Humanos , Idoso , Envelhecimento
11.
Eval Health Prof ; : 1632787231177473, 2023 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-37222735

RESUMO

We aimed to calculate disability-adjusted life expectancy (DALE) for Korean older adults based on their sex, educational attainment, and residential region across their cognitive status. We included 3,854 participants (aged 65-91 years) from the Korean Longitudinal Study of Aging's seventh survey data. The participant's cognitive function status (normal, moderately impaired, or severely impaired) was determined based on cognitive examination and physical function independence, which was used to calculate their DALE. Females with normal cognition had higher DALE (7.60 years, Standard Deviation (SD) = 3.88) than males (6.76, SD = 3.40); however, both sexes had comparable DALE for cognitive impairment. In contrast, the DALE values increased with higher educational achievements. Regarding residential areas, the DALE value for participants with normal cognition and moderate impairment was the highest among urban dwellers, while DALE for participants with severely impaired cognitive function was highest among rural dwellers; however, there were no statistically significant differences based on residential conditions. Our findings suggest that demographic characteristics should be considered when developing health policies and treatment strategies to meet the needs of the aging population in Korea.

12.
J Nanosci Nanotechnol ; 12(2): 1559-62, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22630000

RESUMO

One-dimensional (1-D) nanostructures such as tubes, rods, wires, and belts have attracted considerable research activities owing to their strong application potential as components for nanosize electronic or optoelectronic devices utilizing superior optical and electrical properties. Characterizing the mechanical properties of nanostructure is of great importance for their applications in electronics, optoelectronics, sensors, actuators. Wide-bandgap SnO2 semiconducting material (Eg = 3.6 eV at room temperature) is one of the attractive candidates for optoelectronic devices operating at room temperature, gas sensors, and transparent conducting electrodes. The synthesis and gas sensing properties of semiconducting SnO2 nanomaterials have became one of important research issues since the first synthesis of SnO2 nanobelts. Considering the important application of SnO2 in sensors, these structures are not only ideal systems for fundamental understanding at the nanoscale level, but they also have potential applications as nanoscale sensors, resonator, and transducers. The structured SnO2 nanorods have been grown on silicon substrates with Au catalytic layer by thermal evporation process over 800 degrees C. The resulting sample is characterized and analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and energy-dispersive X-ray spectroscopy (EDS). The morphology and structural properties of SnO2 nanowires were measured by scanning electron microscopy and high-resolution transmission electron microscopy. The mean diameter of the SnO2 nanorods grown on Au coated silicon (100) substrate is approximately 80 nm. In addition, X-ray diffraction measurements show that SnO2 nanorods have a rutile structure. The formation of SnO2 nanowires has been attributed to the vapor-liquid-solid (VLS) growth mechanisms depending on the processing conditions. We investigated the growth behavior of the SnO2 nanowires by variation of the growth conditions such as gas partial pressure and temperature.

13.
Int J Methods Psychiatr Res ; 31(2): e1908, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35278012

RESUMO

OBJECTIVES: This study used the 2016 Korean Longitudinal Study on Aging to investigate the social, behavioural, and functional characteristics of community-dwelling South Korean adults with cognitive impairment. METHODS: Participants were classified as normal, moderate impairment, and severe impairment according to an algorithm that combined the Korean Mini-Mental State Examination score and the number of difficulties in performing instrumental activities of daily living. Selected characteristics included grip strength, depression, participation in exercise and social activities, and living in a rural, urban, or suburban community. RESULTS: Most (72.7%) participants were classified as having normal cognition, 20.1% were classified as moderate impairment, and 7.2% were classified as severe impairment. Regardless of sex, the differences in grip strength across the cognitive status classifications were statistically significant, except for the difference between moderate and severe cognitive impairment in males (p = 0.8477). Greater number of depressive symptoms and living in rural areas were associated with significantly higher odds for severe cognitive impairment. Participants with moderate (OR = 0.51) and severe (OR = 0.33) cognitive impairment were less likely to participate in social activities than those with normal cognition. CONCLUSIONS: The study findings revealed that social, behavioural, and functional characteristics are closely related to the cognitive status of community-dwelling adults in South Korea.


Assuntos
Disfunção Cognitiva , Vida Independente , Atividades Cotidianas , Cognição , Disfunção Cognitiva/epidemiologia , Humanos , Estudos Longitudinais , Masculino , República da Coreia/epidemiologia
14.
Arch Public Health ; 80(1): 81, 2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35287736

RESUMO

BACKGROUND: While divorce is a social determinant of health among married immigrants in Korea, its association with access to healthcare services is unclear. Given the rapid increase in the number of married immigrants in Korea, research is needed to improve minority groups' access to healthcare services. Here, we examined healthcare service utilization among married immigrants. METHODS: We retrieved 11,778 adults from the 2018 Korea National Multicultural Family Survey. We analyzed whether the sex of divorced immigrants is associated with healthcare access using multivariable logistic regression analysis. Further, we analyzed the association between divorce and access to healthcare services among married immigrants using propensity score matching methods. RESULTS: There were 691 (5.8%) divorced immigrants in the data set. The married male immigrants had no association between divorce status and healthcare access (adjusted odds ratio [OR] = 1.05, 95% confidence interval [CI] = 0.55-2.03, p = 0.8620). Divorced immigrants were less likely to receive healthcare services than married immigrants (adjusted OR = 1.42, 95% CI = 1.07-1.88). CONCLUSION: Our findings revealed that divorce increases the risk of limited access to healthcare services among married immigrants. Policymakers and healthcare providers should be aware of these potential disparities in this vulnerable minority population.

15.
Artigo em Inglês | MEDLINE | ID: mdl-36011988

RESUMO

This study aims to develop a universal scale for comparing cognitive and physical functions among countries using health survey data from China, Korea, and Japan. This study used the data of 934 participants from the Korean Longitude Study of Aging, 2506 participants from the China Health and Retirement Longitude Study, and 178 participants from the Japanese Study of Aging and Retirement. Each physical and cognitive function item in the three countries has five key items. The anchoring method used the key items to link each cognitive and physical function of the three countries. We investigated the psychometric characteristics of the final item using the Rasch analysis. We extracted 13 items of 19 cognitive function items and 20 items out of 29 physical function items using the anchoring method and the Rasch analysis. The Rasch analysis showed good fit statistics for 13 cognitive function items and 20 physical function items. The measurement scale developed in this study will enable valid comparisons of older adults' cognitive and physical functions across these three countries.


Assuntos
Pessoas com Deficiência , Idoso , Inquéritos Epidemiológicos , Humanos , Japão , Psicometria/métodos , Reprodutibilidade dos Testes , República da Coreia , Inquéritos e Questionários
16.
OTJR (Thorofare N J) ; 42(4): 344-352, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35904347

RESUMO

Social participation is associated with cognitive function; however, their causal relationships have not been reported yet. This study was designed to examine the autoregressive effects and bidirectional causal relationship between social participation and cognitive function. In this secondary longitudinal data analysis, we enrolled 4,834 Korean adults. A cross-lagged panel model with fixed effects was used to examine the causal relationships between social participation and cognitive function. Both participation (unstandardized coefficient = .370, p < .001) and cognitive function (unstandardized coefficient = .151, p < .001) had positive autoregressive effects over time. Participation had a cross-lagged effect on cognitive function (unstandardized coefficient = .061, p < .001). However, the cross-lagged effects of cognitive function on participation were not statistically significant (unstandardized coefficient = .051, p = .312). Various health-care programs that promote social participation and improve cognitive function must be established. Additional studies are required to confirm the causal effects of cognitive function on participation.


Assuntos
Vida Independente , Participação Social , Adulto , Cognição , Humanos , Participação Social/psicologia
17.
Epidemiol Health ; 44: e2022095, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36317401

RESUMO

OBJECTIVES: This study aimed to investigate health-adjusted life expectancy (HALE) by demographic characteristics (sex, educational achievement, and residential area) according to the lifestyle classifications of the Yonsei Lifestyle Profile-BREF (YLP-BREF). METHODS: This study included 569 participants aged 55 years or older living in Korea. The YLP-BREF domains were physical activity, activity participation, and nutrition. RESULTS: Females had a longer HALE (mean±standard deviation, 8.90±5.06 years) in the physical activity domain, while males had a longer HALE in the nutrition domain (9.44±5.91 years). People living in rural areas had longer HALE in physical activity (12.02±5.60 years), activity participation (8.58±4.21 years), and nutrition (11.33±6.43 years). There were no significant differences according to sex or residential area. High school graduates showed the longest HALE (physical activity: 10.38± 6.89; activity participation: 7.64±4.29; nutrition: 9.59±6.40 years). There was a significant difference in educational achievement. CONCLUSIONS: As people age, the demand for a healthy lifestyle increases. This study attempted to calculate HALE by demographic characteristics according to lifestyle. The results of this study will help inform future research directions for providing a healthy lifestyle.


Assuntos
Expectativa de Vida , Estilo de Vida , Feminino , Humanos , Masculino , Exercício Físico
18.
J Nanosci Nanotechnol ; 11(2): 1648-51, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21456258

RESUMO

The ZnO nanorods have been grown on silicon substrates by a metalorganic chemical vapor deposition (MOCVD) process with/without Au catalytic layer. The growth behavior of ZnO nanorods changed with the catalytic layer. The presence of Au catalyst complicated the growth direction of ZnO nanorods in the MOCVD methods. The ZnO nanorods had single crystalline atomic structure and pure compositions without impurities and strong and narrow excitonic emission. We investigated the growth behavior of the ZnO nanostructures which are leading candidate for optical applications.

19.
J Nanosci Nanotechnol ; 11(8): 7315-8, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22103185

RESUMO

Recently anti-reflective films (AR) have been intensely studied. Particularly for textured silicon solar cells, the AR films can further reduce the reflection of the incident light through trapping the incident light into the cells. In this work, TiO2 anti-reflection films have been grown on the textured Si (100) substrate which is processed in two steps, and the films are deposited using metal-organic chemical vapor deposition (MOCVD) with a precursor of titanium tetra-isopropoxide (TTIP). The effect of the substrate texture and the growth conditions of TiO2 films on the reflectance has been investigated. Pyramid size of textured silicon had approximately 2-9 microm. A well-textured silicon surface can lower the reflectance to 10%. For more reduced reflection, TiO2 anti-reflection films on the textured silicon were deposited at 600 degrees C using titanium tetra-isopropoxide (TTIP) as a precursor by metal-organic chemical vapor deposition (MOCVD), and the deposited TiO2 layers were then treated by annealing for 2 h in air at 600 and 1000 degrees C, respectively. In this process, the treated samples by annealing showed anatase and rutile phases, respectively. The thickness of TiO2 films was about 75 +/- 5 nm. The reflectance at specific wavelength can be reduced to 3% in optimum layer.

20.
J Nanosci Nanotechnol ; 11(12): 10599-603, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22408956

RESUMO

TiO2 surface is led to super-hydrophilic surface by modifying to hydroxyl group. The super-hydrophilic surface can be applied to anti-fogging, because of preventing formation of water droplet on the surface. Super-hydrophilic coatings are made of metal oxides, polymers, or their mixtures. In this study, columnar-structured C doped TiO2 nano-pillars were grown on glass substrates by MOCVD method. For change of surface properties, grown columnar-structured C-TiO2 nano-pillars were treated by oxygen plasma. After oxygen plasma treatment, the surface property of grown columnar structured C-TiO2 nano-pillars changed from hydrophobic surface to super hydrophilic surface. For determination of this mechanism, scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), FT-IR spectroscopy, and contact angle analyzer were employed.

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