Un gruppo di ricercatori della prestigiosa Universita’ Tsinghua di Pechino ha realizzato un LED con grafene in grado di emettere luce in quasi tutto lo spettro visibile: dal blu (450 nm di lunghezza d’onda) al rosso (750 nm lunghezza d’onda). Un tale LED con regolazione del colore non è mai stato realizzato.

The graphene-based LED’s color depends on the applied voltage. The red and blue diagrams show electrons excited to different energy levels, corresponding to different photon energies and therefore different colors of light emission. Credit: Wang, et al. ©2015 Nature

The graphene-based LED’s color depends on the applied voltage. The red and blue diagrams show electrons excited to different energy levels, corresponding to different photon energies and therefore different colors of light emission. Credit: Wang, et al. ©2015 Nature

Gli scienziati hanno prodotto il materiale luminescente sfruttando due diversi composti basati sul grafene: Ossido di Grafene (GO) e Ossido di Grafene “ridotto” (rGO). Tra questi due materiali (GO e rGO) è stato realizzato uno speciale materiale di rGO che ha proprietà ottiche, fisiche e chimiche presenti sia nel GO che nel rGO. La proprietà più importante dello strato d’interfaccia è che ha una serie di livelli energetici discreti che consentono l’emissione di luce a differenti colori.

(Top) The light-emitting layer lies at the interface between graphene oxide (GO) and reduced graphene oxide (rGO). (Bottom) Typical electroluminescent spectra of a single graphene-based LED. Credit: Wang, et al. ©2015 Nature

(Top) The light-emitting layer lies at the interface between graphene oxide (GO) and reduced graphene oxide (rGO). (Bottom) Typical electroluminescent spectra of a single graphene-based LED. Credit: Wang, et al. ©2015 Nature


Questa particolare proprietà è interessante perché né GO nè RGO (o qualunque altra forma conosciuta di grafene) possono emettere luce. Nel loro lavoro, i ricercatori hanno prodotto e testato 20 LED basati su grafene. In generale, i dispositivi hanno dimostrato una buona luminosità, ma una scarsa efficienza. Un altro inconveniente del prototipo corrente è una vita molto breve di emissione di meno di un minuto o poco più in condizioni ambientali e di circa 2 ore nel vuoto. La breve durata sarebbe dovuta all’ossidazione in aria e prevedono che rivestimenti protettivi possano migliorarne le performance.

Fonte: Graphene Info


graphene battery

Great news for e-mobility of the near future, the spanish company Graphenano (industrial-scale graphene production company) developed a new Graphene polymeric lithium battery.

Graphene is the thinnest , hardest material in the world, came out in 2004 , its discoverer , University of Manchester Andre – Heim (AndreGeim) professor who won the Nobel Prize in Physics in 2010.

Such graphene polymeric material has longer battery life, up to four times the conventional lithium batteries. And because of the characteristics of graphene to be very thin (one mono-atomic layer), this battery is only half the weight of conventional batteries, making the load of the car more lightweight , thereby improving vehicle fuel efficiency.

Graphenano company reference person says its cost is not high. It will cost 77% lower than lithium batteries available in the market now.

The material have been developed with the University of Cordoba and the storage capacity reach 3 times the current batteries allowing cars to run for 1000 kilometers and a charging time lower than 8 minutes..

Graphenano company plans to put into production this battery in 2015, rumors says a German car company (not yet disclosed) is testing the battery this month.

Source: Tech.163


I recently read “Graphene is the future, the future is now”. If you already read my posts you will see some strange solid-state graphene based batteries can self-charging. You might think it is only patological science, but here you are an important news from Nokia. We can say this innovation has got truly revolutionary potential.

Nokia is one of the leaders in graphene based research work and mainly on prototyping optical sensor based on graphene. Now Nokia has just patented a self-charging graphene based photon-battery.

The generation of protons is facilitated by the presence of water. The configuration of the GO electrode with the water and the higher pH media renders the battery 300 a dynamic battery. In other words, the battery 300 is capable of regenerating itself immediately after discharge through continuous chemical reactions. In particular, the battery 300 may be automatically charged back to open circuit voltage without an external energy input. The result is a low-power, energy-autonomous device.

It may use humid hair to recharge itself:

During operation, the battery 300 can generate an open circuit voltage on the order of about 1 volt (V) when in the presence of humid air (for example, when the relative humidity is about 30%). The battery 300 also exhibits a fast recovery of its voltage within a few minutes after being fully discharged and without the application of external energy.

If this innovation is not enough, they say it even can be printed on flexible substrates for making a flexible battery or can be made highly transparent.

The battery 300 can be made flexible using printing technology. For example, the battery 300 can be printed onto a flexible substrate. The battery 300 can also be made to have highly transparent optical properties or elastomeric properties.

nokia graphene self-charging battery

Nokia patent graphene based self-charging battery

Nokia pantent