PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Chemists make new silicon-based nanomaterials

Chemists make new silicon-based nanomaterials
2015-03-26
(Press-News.org) PROVIDENCE, R.I. [Brown University] -- In a paper published in the journal Nanoletters, the researchers describe methods for making nanoribbons and nanoplates from a compound called silicon telluride. The materials are pure, p-type semiconductors (positive charge carriers) that could be used in a variety of electronic and optical devices. Their layered structure can take up lithium and magnesium, meaning it could also be used to make electrodes in those types of batteries.

"Silicon-based compounds are the backbone of modern electronics processing," said Kristie Koski, assistant professor of chemistry at Brown, who led the work. "Silicon telluride is in that family of compounds, and we've shown a totally new method for using it to make layered, two-dimensional nanomaterials."

Koski and her team synthesized the new materials through vapor deposition in a tube furnace. When heated in the tube, silicon and tellurium vaporize and react to make a precursor compound that is deposited on a substrate by an argon carrier gas. The silicon telluride then grows from the precursor compound.

Different structures can be made by varying the furnace temperature and using different treatments of the substrate. By tweaking the process, the researchers made nanoribbons that are about 50 to 1,000 nanometers in width and about 10 microns long. They also made nanoplates flat on the substrate and standing upright.

"We see the standing plates a lot," Koski said. "They're half hexagons sitting upright on the substrate. They look a little like a graveyard."

Each of the different shapes has a different orientation of the material's crystalline structure. As a result, they all have different properties and could be used in different applications.

The researchers also showed that the material can be "doped" through the use of different substrates. Doping is a process through which tiny impurities are introduced to change a material's electrical prosperities. In this case, the researchers showed that silicon telluride can be doped with aluminum when grown on a sapphire substrate. That process could be used, for example, to change the material from a p-type semiconductor (one with positive charge carriers) to an n-type (one with negative charge carriers).

The materials are not particularly stable out in the environment, Koski says, but that's easily remedied.

"What we can do is oxidize the silicon telluride and then bake off the tellurium, leaving a coating of silicon oxide," she said. "That coating protects it and it stays pretty stable."

From here, Koski and her team plan to continue testing the material's electronic and optical properties. They're encouraged by what they've seen so far.

"We think this is a good candidate for bringing the properties of 2-D materials into the realm of electronics," Koski said.

INFORMATION:

The paper is available at the following link: http://pubs.acs.org/doi/abs/10.1021/nl504330g Koski's co-authors on the paper were postdoctoral researcher Sean Keuleyan, graduate student Mengjing Wang, and undergraduates Frank Chung and Jeffrey Commons.

Note to Editors:

Brown University has a fiber link television studio available for domestic and international live and taped interviews, and maintains an ISDN line for radio interviews. For more information, call (401) 863-2476.


[Attachments] See images for this press release:
Chemists make new silicon-based nanomaterials

ELSE PRESS RELEASES FROM THIS DATE:

Moffitt Cancer Center research aims to reduce health care disparities

2015-03-26
TAMPA, Fla. - The lesbian, gay, bisexual, transgender/transsexual, queer/questioning and intersex (LGBTQI) population has been largely understudied by the medical community. Researchers at Moffitt Cancer Center found that the LGBTQI community experience health disparities due to reduced access to health care and health insurance, coupled with being at an elevated risk for multiple types of cancer when compared to non-LGBTQI populations. Gwendolyn P. Quinn, Ph.D., scientific director of the Survey Methods Core Facility at Moffitt, identified physicians largely operate ...

Fitness level associated with lower risk of some cancers, death in men

2015-03-26
Men with a high fitness level in midlife appear to be at lower risk for lung and colorectal cancer, but not prostate cancer, and that higher fitness level also may put them at lower risk of death if they are diagnosed with cancer when they're older, according to a study published online by JAMA Oncology. While the association between cardiorespiratory fitness (CRF) and cardiovascular disease (CVD) has been well-established, the value of CRF as a predictor of primary cancer has gotten less attention, according to background in the study. Susan G. Lakoski, M.D., M.S., ...

Deadly Japan quake and tsunami spurred global warming, ozone loss

2015-03-26
WASHINGTON, D.C. - Buildings destroyed by the 2011 Tohoku earthquake released thousands of tons of climate-warming and ozone-depleting chemicals into the atmosphere, according to a new study. New research suggests that the thousands of buildings destroyed and damaged during the 9.0 magnitude earthquake and tsunami that struck Japan four years ago released 6,600 metric tons (7,275 U.S. tons) of gases stored in insulation, appliances and other equipment into the atmosphere. Emissions of these chemicals, called halocarbons, increased by 21 percent to 91 percent over ...

Blood test may shed new light on Fragile X related disorders

2015-03-26
MINNEAPOLIS - A blood test may shed new light on Fragile X syndrome related disorders in women, according to a new study published in the March 25, 2015, online issue of Neurology®, the medical journal of the American Academy of Neurology. Fragile X is the most common inherited form of intellectual disability and the most frequent genetic cause of autism. Fragile X, which is caused by a mutation in a single gene on the X chromosome, affects about 1 in 4,000 men and 1 in 6,000 women. Even more common are Fragile X carriers of a lesser change in the Fragile X gene ...

Female IBD patients: Stay up-to-date on your cervical cancer screening

2015-03-26
Bethesda, MD (March 26, 2015) -- Women with inflammatory bowel disease (IBD) may be at increased risk of cervical dysplasia and cancer, according to a new study1 published in Clinical Gastroenterology and Hepatology, the official clinical practice journal of the American Gastroenterological Association. "Our research shows that patients with IBD, specifically Crohn's disease, are at increased risk for developing cervical cancer, even when undergoing the recommended screening," said study author Professor Tine Jess, MD, from Statens Serum Institut in Denmark. "These findings ...

High-fat diet alters behavior and produces signs of brain inflammation

2015-03-26
Philadelphia, PA, March 26, 2015 - Can the consumption of fatty foods change your behavior and your brain? High-fat diets have long been known to increase the risk for medical problems, including heart disease and stroke, but there is growing concern that diets high in fat might also increase the risk for depression and other psychiatric disorders. A new study published in the current issue of Biological Psychiatry raises the possibility that a high-fat diet produces changes in health and behavior, in part, by changing the mix of bacteria in the gut, also known as ...

How the human immune system keeps TB at bay

2015-03-26
COLUMBUS, Ohio - A new tissue culture model using human white blood cells shows how people with a latent - or symptom-free - tuberculosis infection are protected from active disease by a critical early step in their immune response, researchers say. The model also shows, however, that some TB bacteria can find a way to get around that protection, which helps explain how latent infections turn into active and transmissible disease. More than 2 billion people worldwide are thought to be infected with TB bacteria, and an estimated 1.3 million people died of TB in 2012. ...

Roseroot herb shows promise as potential depression treatment option, Penn team finds

2015-03-26
PHILADELPHIA -- Rhodiola rosea (R. rosea), or roseroot, may be a beneficial treatment option for major depressive disorder (MDD), according to results of a study in the journal Phytomedicine led by Jun J. Mao, MD, MSCE, associate professor of Family Medicine, Community Health and Epidemiology and colleagues at the Perelman School of Medicine of University of Pennsylvania. The proof of concept trial study is the first randomized, double-blind, placebo-controlled, comparison trial of oral R. rosea extract versus the conventional antidepressant therapy sertraline for mild ...

Veterans' avoidant coping interfers with transition to university life

2015-03-26
DENTON (UNT), Texas -- Military veterans who use avoidant coping strategies -- denying or minimizing distressing thoughts, experiences and emotions -- are more likely to exhibit symptoms of depression and generalized anxiety. However, emotional help and support from family members reduces the negative impacts of these conditions, according to a University of North Texas study on veterans' transition to becoming college and university students. Counseling and wellness centers at colleges and universities -- where student veterans may seek help -- should therefore have ...

The Mediterranean diet is not only healthier, it also pollutes less

2015-03-26
The health benefits of the Mediterranean diet are well-known. As well as being healthier, a recent article concludes that the menu traditionally eaten in Spain leaves less of a carbon footprint than that of the US or the United Kingdom. The consequences of climate change range from species extinction to sea-level increases and the spread of diseases. For this reason, researchers have been struggling for years to alleviate its effects, even limiting the pollution caused by food consumption. A new study involving the University Hospital Complex of Huelva, Jaume I University ...

LAST 30 PRESS RELEASES:

Thirty-year mystery of dissonance in the “ringing” of black holes explained

Less intensive works best for agricultural soil

Arctic rivers project receives “national champion” designation from frontiers foundation

Computational biology paves the way for new ALS tests

Study offers new hope for babies born with opioid withdrawal syndrome

UT, Volkswagen Group of America celebrate research partnership

New Medicare program could dramatically improve affordability for cancer drugs – if patients enroll

Are ‘zombie’ skin cells harmful or helpful? The answer may be in their shapes

University of Cincinnati Cancer Center presents research at AACR 2025

Head and neck, breast, lung and survivorship studies headline Dana-Farber research at AACR Annual Meeting 2025

AACR: Researchers share promising results from MD Anderson clinical trials

New research explains why our waistlines expand in middle age

Advancements in muon detection: Taishan Antineutrino Observatory's innovative top veto tracker

Chips off the old block

Microvascular decompression combined with nerve combing for atypical trigeminal neuralgia

Cutting the complexity from digital carpentry

Lung immune cell type “quietly” controls inflammation in COVID-19

Fiscal impact of expanded Medicare coverage for GLP-1 receptor agonists to treat obesity

State and sociodemographic trends in US cigarette smoking with future projections

Young adults drive historic decline in smoking

NFCR congratulates Dr. Robert C. Bast, Jr. on receiving the AACR-Daniel D. Von Hoff Award for Outstanding Contributions to Education and Training in Cancer Research

Chimpanzee stem cells offer new insights into early embryonic development

This injected protein-like polymer helps tissues heal after a heart attack

FlexTech inaugural issue launches, pioneering interdisciplinary innovation in flexible technology

In Down syndrome mice, 40Hz light and sound improve cognition, neurogenesis, connectivity

Methyl eugenol: potential to inhibit oxidative stress, address related diseases, and its toxicological effects

A vascularized multilayer chip reveals shear stress-induced angiogenesis in diverse fluid conditions

AI helps unravel a cause of Alzheimer's disease and identify a therapeutic candidate

Coalition of Autism Scientists critiques US Department of Health and Human Services Autism Research Initiative

Structure dictates effectiveness, safety in nanomedicine

[Press-News.org] Chemists make new silicon-based nanomaterials