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1.
Environ Monit Assess ; 196(7): 613, 2024 Jun 13.
Article in English | MEDLINE | ID: mdl-38871952

ABSTRACT

Physicochemical properties of water influence planktonic diversity and distribution, which is essential in obtaining basic knowledge of aquatic biodiversity. Thus current study aims to investigate the spatiotemporal diversity, abundance ratio, and distribution of phytoplankton species and their association with water quality parameters of Chashma Lake, Pakistan. During the study period from 2018 to 2019, we measured 13 physicochemical parameters across three selected sampling sites (S1, S2, and S3) in Chashma Lake, revealing both spatial and temporal variability. Dissolved oxygen (DO) was higher in S3, while S1 exhibited higher alkalinity levels, carbon dioxide, phosphorus, and chloride levels. The study identified 77 phytoplankton species grouped into five taxonomic categories, with Cyanobacteria dominating (39.90%), followed by Chlorophyta (33.4%) and Bacillariophyta (24.88%). Euglenozoa and Ochrophyta were less abundant (1.3% and 0.41%, respectively). Spatial variations in phytoplankton distribution were noted, with Chlorophyta being more abundant at S2, Bacillariophyta and Cyanobacteria at S1, and Euglenozoa dominating at S3. Canonical Correspondence Analysis (CCA) revealed the influence of various physicochemical parameters on phytoplankton distribution. This comprehensive study provides valuable insights for the ecological assessment and monitoring of water bodies. It is recommended that continuous monitoring is required to capture long-term trends, further explore the specific environmental drivers impacting phytoplankton dynamics, and consider management strategies for maintaining water quality and biodiversity in Chashma Lake.


Subject(s)
Biodiversity , Environmental Monitoring , Lakes , Phytoplankton , Lakes/chemistry , Pakistan , Rivers/chemistry , Cyanobacteria/growth & development , Phosphorus/analysis , Water Quality
2.
Environ Geochem Health ; 46(6): 191, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38696024

ABSTRACT

Pesticides are frequently used to protect crop yields and manage malaria vectors; however, their inadvertent transport into aquatic habitats poses a significant concern. Various anthropogenic activities influence the Indus River in Pakistan. This study aimed to assess the presence of eight pesticide residues at three different sites (Kalabagh, Kundian, and Chashma) in water, sediment, and the fish species (Labeo rohita) during both dry and wet seasons to measure the intensity of this pressure. Pesticide analysis was carried out using gas chromatography equipped with an electron capture detector. The results revealed the highest concentrations of pesticides during both dry and wet seasons at all sites, measuring 0.83 and 0.62 µg/l (water), 12.37 and 9.20 µg/g/dw (sediment), and 14.27 and 11.29 µg/g/ww (L. rohita), respectively. Overall, pesticide concentrations were higher in the dry season than in the wet season across all study sites. Based on detection frequency and concentration in both seasons at all sites, dominant pesticides included cypermethrin and carbofuran (in water), as well as endosulfan and cypermethrin (in sediment and fish tissue). Levels of endosulfan and cypermethrin exceeded standard limits. Moreover, principal component analysis (PCA) indicated no correlation among pesticides in fish tissue, sediment, and water. However, pesticides exhibited different behavior in different seasons. Furthermore, endosulfan and triazophos impose great human health risk, as indicated by the THQ value (> 1). The overall HI value was greater for site 1 in the dry season (8.378). The study concluded that the presence of agricultural pesticides in the Indus River poses a risk to aquatic life and has the potential to disrupt the entire food chain. This highlights the importance of sustainable practices for the study area and Pakistan overall agricultural and environmental sustainability. It is further recommended to strengthen regulations for reduced pesticide use and promote eco-friendly pest management.


Subject(s)
Environmental Monitoring , Geologic Sediments , Pesticides , Rivers , Water Pollutants, Chemical , Geologic Sediments/chemistry , Water Pollutants, Chemical/analysis , Animals , Rivers/chemistry , Pakistan , Humans , Risk Assessment , Pesticides/analysis , Environmental Monitoring/methods , Seasons , Pesticide Residues/analysis , Cyprinidae , Fishes
3.
Biol Trace Elem Res ; 2024 May 06.
Article in English | MEDLINE | ID: mdl-38709368

ABSTRACT

Heavy metal bioaccumulation in organisms is primarily a result of dietary uptake. The current study examines the concentrations of heavy metals (Pb, Cd, Cr, and Cu) in fish feed, water, sediment, and three fish species (Catla catla, Labeo rohita, and Cyprinus carpio) from different feeding zones in a polyculture pond system. Furthermore, associated human health risks were also evaluated. The fish samples (n = 25 for each species) were collected from 10 different fish ponds in the Kohat district, Pakistan. Heavy metals were determined using an atomic absorption spectrometer. Results revealed higher concentrations of heavy metals in sediment, followed by water. However, the concentration of heavy metals in fish feed was lower than the standard limits. In the case of fish, the bottom feeder (C. carpio) notably exhibited higher (P < 0.05) levels of heavy metals than the column feeder (L. rohita) and surface feeder (C. catla) fish. Moreover, in the liver of all fish species, the bioaccumulation of heavy metals was higher, followed by the gills. Principal component analysis (PCA) demonstrated a strong correlation of heavy metals in C. carpio gills, flesh, feed, and pond water, while the heavy metals in the liver correlated with the detected metals in sediment. The human health risk analysis shows that bottom feeder fish had higher estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI) values (> 1). Consequently, the exposed population may experience adverse health effects. The findings of this study suggest that the bottom feeder (C. carpio) bioaccumulates a higher concentration of heavy metals than column (L. rohita) and surface feeder (C. catla) in the polyculture system.

4.
Biol Trace Elem Res ; 202(2): 725-735, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37178449

ABSTRACT

Worldwide, anthropogenic activities are causing the natural environment and aquaculture systems to become heavily contaminated with heavy metals, which can lead to consumer's health problems. In the current study, wild and farmed fish (n = 30) and water samples (n = 6) have been collected from the Chashma barrage and fish farm to assess the heavy metals concentration, i.e., Cu, Cd, Pb, Zn and Cr, in the water and some important organs (gills, liver, muscle, brain and bones) of wild and farmed fish (Labeo rohita) using Graphite furnace Atomic absorption spectrometry. Bioaccumulation factor and human health risk assessment were calculated to measure the health status of both fish and humans. Results show that in wild and farm fish's gills, muscles and bones, the trend of the heavy metals was Zn > Pb > Cu > Cd > Cr. On the other hand, the brain and liver show Zn > Cu > Pb > Cd > Cr trend. Comparatively, the heavy metals concentration was mostly higher (P < 0.05) in wild fish. Further; in both fish habitats (water) the heavy metals (Cd and Pb) concentration was higher than the WHO standard level, while in the body, Cd was higher (P < 0.05) in all studied organs except the muscle, Cr was only lower (P > 0.05) in muscle and brain. Pb was higher (P < 0.05) in all studied organs of both fish. Bioaccumulation of heavy metals was mostly higher (P < 0.05) in wild fish than in farmed. EDI and THQ were higher in wild fish, but the HI value was lower than 1 for both fish. Moreover, the PCA analysis suggests a positive correlation between heavy metals concentration in fish organs and the water of both fish (wild and farmed). Results indicated that farmed fish showed less potential risk to humans than wild fish.


Subject(s)
Cyprinidae , Metals, Heavy , Water Pollutants, Chemical , Animals , Humans , Water , Bioaccumulation , Cadmium/analysis , Lead/analysis , Metals, Heavy/analysis , Risk Assessment , Water Pollutants, Chemical/analysis , Environmental Monitoring/methods
5.
Biol Trace Elem Res ; 202(4): 1741-1751, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37452268

ABSTRACT

Fish meat is a major and rich source of white protein; its quality is determined by the fish feed. However, the low-quality feed may contribute to a source of contamination if it does not fulfill the standard protocol. Biofloc is considered one of the most efficient, successful aquacultures, but this system is still under investigation for its efficiency and safety. Thus, current study focused on the heavy metal contamination in biofloc fish fed on different commercial feeds and human health risk analysis. Samples of extensively used three feeds (Supreme™, Hitech™, and MH-Aqua™), tanks water, and biofloc fish (gills, liver muscle) were collected for heavy metals (Cu, Cd, Pb, and Cr) analysis using atomic absorption spectrometry. An experiment was designed by dividing the fish into three groups: group 1 (Supreme™), group 2 (Hitech™), and group 3 (MH-Aqua™). A bioaccumulation factor and human health risk assessment have been calculated to measure fish and human health. Results revealed that most of the heavy metal concentration was higher (P < 0.05) in MH-Aqua™ feed compared to others. Similarly, heavy metal concentration was higher (P < 0.05) in the water of group 3, where fish was cultured on MH-Aqua™ feed. However, in the fish gills, liver, and muscle, the heavy metal concentration was significantly greater in group 3 fed on MH-Aqua™ feed, followed by group 1. Heavy metals in all feeds were positively correlated to the heavy metal concentration of the fish muscles. The bioaccumulation factor for Cu and Pb was higher in the fish liver, Cd and Cr in the case of fish gills, and least in the fish muscle. EDI and THQ values vary in all the groups, while the HI value was found lower than 1 in group 1 and group 2 but higher in group 3 fed on MH-Aqua™ feed. Strict checks and balances in formulating a diet will be helpful to progressively lower the amount of dangerous heavy metals.


Subject(s)
Cichlids , Metals, Heavy , Water Pollutants, Chemical , Humans , Animals , Cichlids/metabolism , Cadmium/analysis , Incidence , Lead/analysis , Metals, Heavy/analysis , Aquaculture , Risk Assessment , Water/metabolism , Water Pollutants, Chemical/analysis , Environmental Monitoring/methods
6.
Saudi Pharm J ; 31(9): 101702, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37533493

ABSTRACT

Scopolamine is a well-known pharmacological agent responsible for causing memory impairment in animals, as well as oxidative stress and neuroinflammation inducer which lead to the development of Alzheimer disease. Although a cure for Alzheimer's disease is unavailable. Ranuncoside, a metabolite obtained from a medicinal plant has demonstrated antioxidant and anti-inflammatory properties in vitro, making it a promising treatment with potential anti-Alzheimer disease properties. However, as ranuncoside has not been evaluated for its antioxidant and anti-neuroinflammatory properties in any in vivo model, our study aimed to evaluate its neurotherapeutic efficacy against scopolamine-induced memory impairment in adult male albino mice. Mice were randomly divided into four experimental groups. Mice of group I was injected with saline, group II was injected with scopolamine (1 mg/kg/day) for 3 weeks. After receiving a daily injection of scopolamine for 1 week, the mice of group III were injected with ranuncoside (10 mg/kg) every other day for 2 weeks along with scopolamine daily and group IV were injected with ranuncoside on 5th alternate days. Behavioral tests (i.e., Morris water maze and Y-maze) were performed to determine the memory-enhancing effect of ranuncoside against scopolamine's memory deleterious effect. Western blot analysis was also performed to further elucidate the anti-neuroinflammatory and antioxidant effects of ranuncoside against scopolamine-induced neuroinflammation and oxidative stress. Our results showed memory-enhancing, anti-neuroinflammatory effect, and antioxidant effects of ranuncoside against scopolamine by increasing the expression of the endogenous antioxidant system (i.e., Nrf2 and HO-1), followed by blocking neuroinflammatory markers such as NF-κB, COX-2, and TNF-α. The results also revealed that ranuncoside possesses hypoglycemic and hypolipidemic effects against scopolamine-induced hyperglycemia and hyperlipidemia in mice as well as scopolamine's hyperglycemic effect. In conclusion, our findings suggest that ranuncoside could be a potential agent for the management of Alzheimer's disease, hyperglycemia, and hyperlipidemia.

7.
Environ Sci Pollut Res Int ; 30(45): 100646-100659, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37639089

ABSTRACT

Overuse of fertilizers on agricultural lands and fish ponds may result in serious pollution problems, such as heavy metals that can enter the food chain and pose serious health problems. Due to this, the present study investigates the incidence of heavy metals in commonly used fertilizers and its association with heavy metals in vegetables, soil, fish species, and pond water. Samples were collected from different sites (fields and ponds) in district Kohat, where the application of fertilizers was common and control groups (no fertilizers used). Heavy metal analysis was carried out through a spectrophotometer. Results showed higher Cd and Cr concentrations in triple superphosphate (TSP), Cu and Pb in nitrogen, phosphorus, and potassium (NPK), while lower concentrations were found in gypsum. In vegetables (onion, tomato, brinjal, and potato) and associated soil, most of the heavy metals concentrations were significantly higher (P < 0.05) in fertilizer-applied sites than in the control. Also, the Cd concentration in potatoes and Pb level in all vegetables obtained from sites were greater than the WHO/FAO standard limit. In the case of fish species (Hypophthalmichthys molitrix and Cyprinus carpio) muscles and their habitat (water), all the understudy heavy metals were notably higher (P < 0.05) in fertilizer-applied sites (ponds) than the control group. Collectively, in all vegetables and muscles of fish species, the bioaccumulation factor was higher in sites compared to the control. The estimated daily intake (EDI) and target hazard quotient (THQ) values were also higher in fertilizer-applied sites (fields and ponds) than control. The health index (HI) value was > 1 in vegetables (onion, tomato, and potato) and fish muscles collected from different sites compared to the control. Thus, there is the possibility of severe health risks. The use of fertilizers must be carefully monitored in order to ensure that humans and animals are safe from exposure to heavy metals.

8.
Heliyon ; 9(6): e16930, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37416682

ABSTRACT

No effective drug treatment is available for Alzheimer disease, thus the need arise to develop efficient drugs for its treatment. Natural products have pronounced capability in treating Alzheimer disease therefore current study aimed to evaluate the neuro-protective capability of folicitin against scopolamine-induced Alzheimer disease neuropathology in mice. Experimental mice were divided into four groups i.e. control (single dose of 250 µL saline), scopolamine-administered group (1 mg/kg administered for three weeks), scopolamine plus folicitin-administered group (scopolamine 1 mg/kg administration for three weeks followed by folicitin administration for last two weeks) and folicitin-administered group (20 mg/kg administered for 5 alternate days). Results of behavioral tests and Western blot indicated that folicitin has the capability of recovering the memory against scopolamine-induced memory impairment by reducing the oxidative stress through up-regulating the endogenous antioxidant system like nuclear factor erythroid 2-related factor and Heme oxygenase-1 while prohibiting phosphorylated c-Jun N-terminal kinase. Similarly, folicitin also improved the synaptic dysfunction by up-regulating SYP and PSD95. Scopolamine-induced hyperglycemia and hyperlipidemia were abolished by folicitin as evidenced through random blood glucose test, glucose tolerance test and lipid profile test. All these results revealed that folicitin being a potent anti-oxidant is capable of improving synaptic dysfunction and reducing oxidative stress through Nrf-2/HO-1 pathway, thus plays a key role in treating Alzheimer disease as well as possess hyperglycemic and hyperlipidemic effect. Furthermore, a detailed study is suggested.

9.
Nat Prod Res ; 37(5): 803-808, 2023 Mar.
Article in English | MEDLINE | ID: mdl-35707892

ABSTRACT

This study aimed to assess the Withania coagulans fruit extract's effects on growth and haematological parameters of Labeo rohita. Healthy fish (n = 120) were divided in four groups. Experimental diet was prepared with different extraction of W. coagulans (0%, 1%, 1.5% and 2%). Diet was provided for eight weeks to all groups except the control group which fed on basal diet. The 1.5% and 2% W. coagulans extracts lead improvement in feed conversion ratio and specific fish growth rate; haematological parameters in fish group fed with 2% of W. coagulans showed increased in WBC, RBC, Hb, MCHC, PCV. The values of plasma proteins and lysozyme activity were higher in the experimental group compared control group. Fish fed with W. coagulans extracts showed increased of immunity and less mortality respect to others. It suggested that W. coagulans could be considered valuable support for the improve growth and immunity in Labeo rohita.


Subject(s)
Cyprinidae , Withania , Animals , Fruit , Animal Feed/analysis , Diet , Plant Extracts/pharmacology
10.
Biol Trace Elem Res ; 200(5): 2432-2438, 2022 May.
Article in English | MEDLINE | ID: mdl-34373978

ABSTRACT

The current study aims to assess the cadmium sub-lethal concentration influence on growth and haematological and biochemical parameters of Mystus seenghala. A total of 60 fish of three different length groups (20 each) were collected from Head Qadirabad, Pakistan. The fish were treated to the sub-lethal concentration viz. one-third of LC50, for 16 weeks except for the control groups. Water quality parameters were kept constant during the entire course of the research, and the major parameters were measured as temperature (28.03 ± 0.03 °C), DO (5.82 ± 0.14 mg L-1), pH (8.00 ± 0.01) and total hardness (249.98 ± 0.01 mg L-1). Findings revealed that the growth of three treated variant length groups was affected negatively by cadmium exposure and showed significantly (P < 0.05) lower average wet weight, body length and condition factor as compared to control groups, while the feed conversion ratio (FCR) increases by increasing the exposure duration. The haematological parameters including values of Hct, Hb and MCHC were significantly (P < 0.05) reduced in all Cd-treated groups than control groups, whereas the level of MCH and MCV were significantly higher, but no significant difference was found in the value of RBCs in all treated groups. Biochemical parameters such as ALT, AST, total lipid and glucose level in Cd exposure groups were significantly higher, while the total protein level was significantly (P < 0.05) reduced in all treated groups as compared to control groups. From the current study, it has been concluded that the growth, haematology and biochemical parameters are important indicators of ecotoxicology particularly contamination of the cadmium and health of the fish.


Subject(s)
Cadmium , Erythrocytes , Animals , Cadmium/toxicity , Pakistan
11.
Cell Mol Biol (Noisy-le-grand) ; 68(10): 15-20, 2022 Sep 30.
Article in English | MEDLINE | ID: mdl-37114278

ABSTRACT

The insecticide, cypermethrin, adversely affects biochemical parameters in blood and behavior in grass carp (Ctenopharyngodon idella). Fish were obtained from hatchery, reared in the laboratory. Different concentration of cypermethrin were applied. Blood was collected and hematological and biochemical parameters were measured. Biochemical parameters such as, protein levels, cholesterol, phosphorous and calcium in both acute and chronically cypermethrin treated groups decreased, with increasing exposure time from 24h to 15 days with more pronounced effects in the acute groups. Increased glucose, urea, serum glutamic pyruvic transaminase (SGPT), creatinine, and lactate dehydrogenase (LDH) levels were found in both acute and chronic groups with the increasing exposure time. Hematological parameters, such as red blood cell (RBC), hemoglobin (HGB), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MHCH), and red cell distribution width (RDW) were significantly reduced in both groups as the exposure time increases. However, the numbers of white blood cells (WBC) and platelets were increased. This study established both the acute and chronic toxicity of cypermethrin in grass carp, which likely occurs secondary to altered biochemical and blood parameters.


Subject(s)
Carps , Hematology , Animals , Hematocrit , Fresh Water
12.
J Arthropod Borne Dis ; 16(1): 34-44, 2022 Mar.
Article in English | MEDLINE | ID: mdl-36636243

ABSTRACT

Background: Mosquitoes (Diptera: Culicidae) are haemotophagus insects and are vectors of many arthropod-borne diseases. Present study aimed to explore species composition, seasonal abundance, spatial distribution and physio-chemical properties of larval breeding sites of mosquitoes in District Mardan, Khyber Pakhtunkhwa, Pakistan. Methods: Both adults and larvae of mosquitoes were collected through light traps, insecticide spray, mouth aspirator and larval standard dipping method in District Mardan from May to November 2017. Water samples from larval sites were physio-chemically analysed. Results: 5078 (3704 adults and 1374 larvae) mosquito specimens were collected in Mardan, Katlang and Takhtbhai tehsils. Six species in four genera were reported. Culex pipiens (89.80%) and Armigeres subalbatus (9.20%) were the most abundant species. Diversity was high in Takhtbhai (0.29) followed by Katlang (0.28) and Mardan (0.25). Greater number of specimens were recorded in peridomestic sites (93.97%) as compared to domestic habitats (6.03%). Culex pipiens larval abundance had negative correlation with pH whereas it correlated positively with electric conductivity, salinity, and TDS (total dissolved sulphur). Mosquito abundance peaked in August and July while the lowest was in May. Their monthly abundance had positive correlation with rainfall (r= 0.5069), relative humidity (r= 0.4439) and mean minimum temperature (r= 0.2866). Number of mosquitoes was highest at low elevation < 347m asl (above sea level) in agriculture land and near to water bodies (streams). Conclusion: Culex pipiens being the most abundant species, was susceptible to high pH. Mosquitoes preferred habitats were at low elevation in agriculture land.

13.
Animals (Basel) ; 11(5)2021 May 01.
Article in English | MEDLINE | ID: mdl-34062790

ABSTRACT

The aim of the current study was to assess the effect of two different fortified feeds with different concentrations of two important medicinal plants (Withania coagulans and Zingiber officinale) on the mucosal immunity of Labeo rohita. After a dietary intervention, mucus was tested against five pathogenic bacteria (in-vitro), while experimental fish were tested against the ectoparasite (Lernaea) (in-vivo). Our results revealed that all fish groups fed with different concentrations (1, 1.5, and 2%) of Z. officinale had low molecular weight proteins and did not develop any significant signs of parasitic infection, with low mortality rate; whereas the groups that were fed with W. coagulans (particularly with 1% and 2%), including a control group, developed rapid signs of infection with high mortality rate. The highest hemagglutination titer value was recorded for the fish fed with 1% and 1.5% of Z. officinale. The lowest value was found for the fish fed with 2% of W. coagulans. The mucus of all fish of fortified groups was active and inhibited the growth of tested bacterial pathogens as compared to the control group. Further, Z. officinale groups showed greater efficacy against bacteria as compared to the W. coagulans groups. In conclusion, Z. officinale can be considered as a potential and functional ingredient in aquaculture feed. Furthermore, future studies should be conducted to investigate more details on the subject.

14.
Adv Mater ; 27(42): 6677-82, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26400042

ABSTRACT

Area emission is realized in all-solution-processed hybrid light-emitting transistors (HLETs). A new HLET design is presented with increased aperture ratio, and optical and electrical characteristics are shown.

15.
Adv Mater ; 27(41): 6390-5, 2015 Nov 04.
Article in English | MEDLINE | ID: mdl-26392063

ABSTRACT

A solution-processable dibromoindigo with an alkyoxyphenyl solubilizing group is developed and used as a new electron acceptor in organic photodiodes. The solution-processed fullerene-free organic photodiodes show an almost spectrally flat response with a high responsivity (0.4 A W(-1)) and a high detectivity (1 × 10(12) Jones). These values are comparable to silicon-based photodiodes.


Subject(s)
Fullerenes/chemistry , Indigo Carmine/chemistry , Gold/chemistry , Polystyrenes/chemistry , Solar Energy , Solutions/chemistry , Thiophenes/chemistry , Tin Compounds/chemistry , Transistors, Electronic
16.
Sci Rep ; 5: 8818, 2015 Mar 06.
Article in English | MEDLINE | ID: mdl-25743444

ABSTRACT

Light-emitting field effect transistors (LEFETs) are an emerging class of multifunctional optoelectronic devices. It combines the light emitting function of an OLED with the switching function of a transistor in a single device architecture. The dual functionality of LEFETs has the potential applications in active matrix displays. However, the key problem of existing LEFETs thus far has been their low EQEs at high brightness, poor ON/OFF and poorly defined light emitting area - a thin emissive zone at the edge of the electrodes. Here we report heterostructure LEFETs based on solution processed unipolar charge transport and an emissive polymer that have an EQE of up to 1% at a brightness of 1350 cd/m(2), ON/OFF ratio > 10(4) and a well-defined light emitting zone suitable for display pixel design. We show that a non-planar hole-injecting electrode combined with a semi-transparent electron-injecting electrode enables to achieve high EQE at high brightness and high ON/OFF ratio. Furthermore, we demonstrate that heterostructure LEFETs have a better frequency response (f cut-off = 2.6 kHz) compared to single layer LEFETs. The results presented here therefore are a major step along the pathway towards the realization of LEFETs for display applications.

17.
Adv Mater ; 26(37): 6410-5, 2014 Oct 08.
Article in English | MEDLINE | ID: mdl-24899533

ABSTRACT

All solution-processed, high performance hybrid light emitting transistors (HLETs) are realized. Using a novel combination of device architecture and materials a bilayer device comprised of an inorganic and organic semiconducting layer is fabricated and the optoelectronic properties are presented.

18.
Adv Mater ; 25(43): 6213-8, 2013 Nov 20.
Article in English | MEDLINE | ID: mdl-23963863

ABSTRACT

An innovative design strategy for light emitting field effect transistors (LEFETs) to harvest higher luminance and switching is presented. The strategy uses a non-planar electrode geometry in tri-layer LEFETs for simultaneous enhancement of the key parameters of quantum efficiency, brightness, switching, and mobility across the RGB color gamut.


Subject(s)
Luminescent Measurements/instrumentation , Transistors, Electronic , Color , Electrodes , Gold/chemistry , Polymers/chemistry , Thiophenes/chemistry
19.
Synth Met ; 161(23-24): 2562-2565, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22368321

ABSTRACT

A comprehensive study concerning the reproducibility and stability of organic n-type field effect transistors is presented. C(60) based OFETs were chosen to investigate the fabrication reproducibility and the long term stability because C(60) is a high mobility n-type material. We fabricated 48 transistors and each transistor was measured for 24 h inside the glove box. To test for life time stability - long term measurements up to three months have been undertaken. We report about the fluctuations in the device parameters of all investigated transistors by comparing the transfer characteristics, and on/off ratio for short time and long time measurements. C(60) based OFETs showed good reproducibility and stability for short time measurements and a decay for long time measurements.

20.
Org Electron ; 13(5): 919-924, 2012 May.
Article in English | MEDLINE | ID: mdl-23483783

ABSTRACT

We report on the fabrication and performance of vacuum-processed organic field effect transistors utilizing evaporated low-density polyethylene (LD-PE) as a dielectric layer. With C60 as the organic semiconductor, we demonstrate low operating voltage transistors with field effect mobilities in excess of 4 cm2/Vs. Devices with pentacene showed a mobility of 0.16 cm2/Vs. Devices using tyrian Purple as semiconductor show low-voltage ambipolar operation with equal electron and hole mobilities of ∼0.3 cm2/Vs. These devices demonstrate low hysteresis and operational stability over at least several months. Grazing-angle infrared spectroscopy of evaporated thin films shows that the structure of the polyethylene is similar to solution-cast films. We report also on the morphological and dielectric properties of these films. Our experiments demonstrate that polyethylene is a stable dielectric supporting both hole and electron channels.

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