{"id":3936,"date":"2015-12-03T04:36:58","date_gmt":"2015-12-03T04:36:58","guid":{"rendered":"http:\/\/www.kurzweilai.net\/?p=267902"},"modified":"2015-12-03T04:36:58","modified_gmt":"2015-12-03T04:36:58","slug":"white-graphene-graphene-super-thin-cooler-more-flexible-electronics","status":"publish","type":"post","link":"https:\/\/hoo.central12.com\/fugic\/2015\/12\/03\/white-graphene-graphene-super-thin-cooler-more-flexible-electronics\/","title":{"rendered":"White graphene + graphene –> super-thin, cooler, more flexible electronics"},"content":{"rendered":"
\"\"<\/a>

Growth and transfer of 2-D material such as hexagonal boron nitride and graphene was performed by a team that included Yijing Stehle of Oak Ridge National Laboratory. (credit: ORNL)<\/p><\/div>\n

A new era of electronics and even quantum devices could be ushered in with the fabrication of a virtually perfect single layer of \u201cwhite graphene,\u201d according to researchers at the Department of Energy\u2019s Oak Ridge National Laboratory.<\/p>\n

The material is technically known as hexagonal boron nitride (see “New inventions track greenhouse gas, remediate oil spills<\/a>“). It is an insulator (instead of a conductor of electricity as with graphene), so it could serve as a 2-D dielectric (insulating material) in electronic devices such as thin-film capacitors.<\/p>\n

It also has even better transparency than graphene, making it useful as a substrate and the foundation for the electronics in cell phones, laptops, tablets and many other devices.<\/p>\n

“As thin as a piece of paper”
\n<\/strong><\/p>\n

ORNL\u2019s Yijing Stehle, postdoctoral associate and lead author of a paper published in\u00a0Chemistry of Materials<\/em> and colleagues are working on combining graphene and boron nitride in a 2-D capacitor and fuel cell prototype that are \u201csuper thin\u201d and also transparent.<\/p>\n

With their recipe for white graphene, ORNL researchers hope to unleash the full potential of graphene as a conductor. By combining it with white graphene as a substrate, researchers believe they can make thinner, more-flexible multilayer electronic devices.<\/p>\n

“Imagine batteries, capacitors, solar cells, video screens and fuel cells as thin as a piece of paper,\u201d she said.<\/p>\n

For its part, graphene on\u00a0a white-graphene substrate also has several thousand times higher electron\u00a0mobility than using graphene on other substrates. That feature could enable data transfers that are much faster than what is available today.<\/p>\n

Cool electronics<\/strong><\/p>\n

A recent theoretical study led by Rice University proposed the use of white graphene to cool electronics (see “Why \u2018white graphene\u2019 structures are cool<\/a>“). Stehle and colleagues have made high-quality layers of hexagonal boron nitride that support that study; they believe the material can be cost-effectively scaled up to large production volumes.<\/p>\n

The Rice process consists of standard atmospheric pressure chemical vapor deposition with a similar furnace, temperature and time. But Stehle describes \u201ca more gentle, controllable way to release the reactant into the furnace and figuring out how to take advantage of inner furnace conditions.\u201d<\/p>\n

New Mexico State University researchers were also involved in the study, which was supported by\u00a0the DOE’s Office of Science.<\/p>\n

\n

Abstract of\u00a0Synthesis of Hexagonal Boron Nitride Monolayer: Control of Nucleation and Crystal Morphology<\/em><\/h4>\n

Monolayer hexagonal boron nitride (hBN) attracts significant attention due to the potential to be used as a complementary two-dimensional dielectric in fabrication of functional 2D heterostructures. Here we investigate the growth stages of the hBN single crystals and show that hBN crystals change their shape from triangular to truncated triangular and further to hexagonal depending on copper substrate distance from the precursor. We suggest that the observed hBN crystal shape variation is affected by the ratio of boron to nitrogen active species concentrations on the copper surface inside the CVD reactor. Strong temperature dependence reveals the activation energies for the hBN nucleation process of \u223c5 eV and crystal growth of \u223c3.5 eV. We also show that the resulting h-BN film morphology is strongly affected by the heating method of borazane precursor and the buffer gas. Elucidation of these details facilitated synthesis of high quality large area monolayer hexagonal boron nitride by atmospheric pressure chemical vapor deposition on copper using borazane as a precursor.<\/p>\n","protected":false},"excerpt":{"rendered":"

A new era of electronics and even quantum devices could be ushered in with the fabrication of a virtually perfect single layer of “white graphene,” according to researchers at the Department of Energy’s Oak Ridge National Laboratory. The material is technically known as hexagonal boron nitride (see “New inventions track greenhouse gas, remediate oil spills“). […]<\/p>\n","protected":false},"author":13,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[48,55,43],"tags":[],"class_list":["post-3936","post","type-post","status-publish","format-standard","hentry","category-electronics","category-nanotechmaterials-science","category-news"],"_links":{"self":[{"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/posts\/3936"}],"collection":[{"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/users\/13"}],"replies":[{"embeddable":true,"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/comments?post=3936"}],"version-history":[{"count":1,"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/posts\/3936\/revisions"}],"predecessor-version":[{"id":3937,"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/posts\/3936\/revisions\/3937"}],"wp:attachment":[{"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/media?parent=3936"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/categories?post=3936"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/tags?post=3936"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}