22 01 2013

As promised, here is the update for the exciting news in 2013.

At the end of 2012, we joined the space exploration project being run by JP Aerospace in California and launched some pongsats with our local scouts. We flew all kinds of stuff, from bouncy balls to a troll (don’t ask) in our balls, but perhaps the most interesting was the six axis solar intensity monitor. This was built by a work experience student, who managed to make it onto the BBC local news back in October. This was so successful, we got the bug and when we saw the ‘Ideas Take Flight‘ strapline for the upcoming British Science Festival, the thought was ‘how high?’

This has resulted in a big project, with some twenty teams developing cubesats to launch up to around 100,000 feet sometime in June

British Science Festival space cubesat ideas

Ideas Take Flight … to the Edge of Space

So far, we have held a big kick off event in the Discovery Museum and followed this up with visits to schools and this last week, schools visiting us. Next step, is that we need to think carefully about the circuitry before we all meet up again to squeeze it all in to a 2″ cube.

The last update for today, is that I received my new toy in the post yesterday. Molybdenum Disulphide, potentially the next graphene, is being touted as the next wonder material. A trip to the clean room tomorrow and hopefully we should be up and running in this exciting field by this time next week.

MoS2 Molybdenum Disulphide crystal 2D electronics

Natural Molybdenum Disulphide Crystals


ICSCRM 2011 – Day FOUR

16 09 2011

Well  today began with the usual sweet breakfast treats (I now love muffins and bagels…jokes) and as we were joined by Kurt and Nick for breakfast I ditched Lucy as she had some important talks to go to including the first of the day on Phosphorus doped gate oxides in 4H-SiC MOSFETs. While Lucy was hard at work Kurt, Nick and I relaxed whilst discussing American geographical history and Kurt’s experience in driving all the way from east coast to west coast in about three days!

After the mid morning break we attended a few talks on defects and reliability and then spent some time organizing all of the photographs and information we had gathered so far.

At lunch we met some very interesting characters from a range of different backgrounds, which brought up a very opinionated discussion on graphene and its potential in future technologies. Unlike me there were several skeptics present but I think I managed to convince them of its uses.

The afternoon had some very interesting talks for both Lucy and I and it was very refreshing to not have to present any posters! I attended some talks on sensors and LEDs where guys from NASA presented high temperature wire bonding and packaging technologies, which was of great relevance and interest to us. Lucy attended another MOS processing and characterisation session, which was also very useful in many ways particularly the discussion of ways to improve the oxide quality in MOS devices. Options which were discussed both experimental and theoretical investigations into the use of of sodium, rubidium, phosphorus and potassium in gate oxides to improve oxide quality.

The final session of the day was the most important of the week for me as it was 2 hours completely dedicated to Graphene devices and practical applications. The highlights of the afternoon were the talks from  IBM on graphene integrated circuits and a talk from Joshua Robinson on graphene field effect transistors. It is very exciting to be surrounded with so much interest and advancement in the area of graphene and it has definitely motivated me and given me many ideas for my future work in my project.

To top off a good day, the conference banquet was held at the Rock and Roll Hall of Fame by the waterfront in Cleveland. The food was great and we got plenty of time to explore the exhibitions. Once again I also had the opportunity to discuss graphene research with Kurt and Yu-Ming Lin from IBM, which a fabulous opportunity to question some intelligent graphene minds, whilst Lucy pretended to understand the discussions!

I’ll be updating soon with information on the location of ICSCRM 2013 when it is announced at the end of the conference closing plenary.


15 09 2011

After having a standard American Breakfast (Bagel and a Muffin), third day of the conference started off with an important session related to Lucy’s MOS work, with talks on Frequency-Dependent Charge Pumping, Temperature Dependent Hall Mobility in SiC MOSFETs. While she attended the second session on MOS processing and characterisation, I attended the important parallel session on graphene growth and characterisation.

During the session, Kurt invited me to join him for lunch, where i met one of his post-doc’s Luke Nyakiti (XPS and Raman Spectroscopist on graphene).  Had a very crucial and lengthy discussion with him about Raman imaging and analysing graphene layers.

Later in the afternoon, Lucy and I presented Ben’s and HK’s posters, while Nick presented Simon’s. Again, all our posters were very well received, and this time around Ben’s work on SiC Hydrogen gas sensors has attracted much attention from the audience.  So again Lucy was busy exchanging quite a few business cards with them.


Lucy prepares for questions on Ben's poster

Looks like people are still in Lucy’s poster hangover (presented on monday), as one of the researchers (Dr. Ruby Ghosh) from Michigan State University approached her to discuss about her work in detail and wanted to be in touch even after the conference!!

So far, conference has been really great…meeting new people, exploring new ideas and opportunities. Apart from the conference, we are being treated as guests to the city in restaurants and couple of them even offered extra “diet coke” for free :).  Oh Apparently, people in Cleveland like Lucy’s accent and they think she’s Australian!!!!!!

Tomorrow has got the biggest session of whole conference on Graphene Devices, which will be chaired by Kurt….can’t wait to be there!!


ICSCRM 2011 – Day TWO

14 09 2011

Second day of the conference started off with a couple of interesting talks on Graphene. In the first talk, they observed how graphene grown on n-type SiC and p-type SiC effects its I-V characteristics and its corresponding temperature behaviour. The second talk focused on intercalation of Ge atoms between SiC and Graphene layer to achieve ambipolar behaviour in epitaxial graphene.   We attended few more talks after this session on  SiC based BJTs and VJEFETs.

Then we had a very nice Lunch with Kurt, Travis, Ginger (all from NRL), Nick wright, Michael Briere (from international rectifiers inc) and some other guys from Keithley…..most part of our discussion during the lunch was on graphene, crazy american sports and Kurt’s unsuccessful attempts to be in the college American football team during his college days!!

After that i had an important meeting with Kurt about my project and then he introduced me to his big team of researchers. Had a very lengthy intriguing discussion about the graphene growth, and characterisation techniques with them, and some other serious players in graphene research from gremany joined in, which spiced up the whole discussion.

Later in the evening Lucy and I presented posters on Omid’s and Amits research work. Considering the fact that neither of us are experts in the field of DC-DC converters or Diamond,  both posters were decently received by the audience.

After the poster session, we went out for dinner with Raytheon guys and then to ‘Dow Corning’ Blues party. Then returned back to hotel tired. We are still struggling to adjust to the time variation 😦

After a very useful and pleasing day, tomorrow, i’ll be presenting HK’s poster on Noise and Lucy will be presenting Ben’s work on SiC sensors and simon’s SiC solar cells.


ICSCRM 2011 – Day ONE

13 09 2011

Hello everyone, i’m Kartheek, one of the lucky ones from our research group to attend this year’s ICSCRM in Cleveland. I’m in charge of five posters from the group and Lucy will be handling the other five.

Today I presented two posters including my work on Graphene chemical sensors and Dan’s SiC Oscillator. Lucy presented hers on n and p channel MOSFETs and Chris’s work on SiO2/SiC interface on illumination.  It was bit of a challenge for us to manage all four posters at the same time. However, have to say all our posters were really well received and especially Lucy’s work on MOSFETs has got such an incredible attention from the audience that she even ran out of her business cards and had to come to me to have some more.

Apart from the posters, one of the opening plenary talks in the morning session on ‘ role of wide bandgap semiconductors for clean energy innovation’ from the newly formed US govt agency ‘ARPA-Energy’ was very exciting. They are working on some ridiculously funded ($400 million) projects such as, better efficient batteries for energy storage in transportation, cost effective grid scale energy storage, exploration of materials for soft magnetics, high voltage switches, and electrofuels.

We also attended the afternoon session on MOSFETs, where i tried to record the talks but soon my memory card ran out of memory 😦 However, the work no 3C-SiC MOSFETs was really impressive, with channel mobilities of around 370cm2V-1s-1 at room temperature. This is close to ten times those seen in 4H-SiC and whilst the ultimate operating temperature might be lower in 3C than 4H, the ability to operate at 300C will open up a significant market for ‘beyond silicon’ electronics.

3C MOSFET mobility

3C MOSFET mobility

Second day of the conference (tomorrow) starts with an intriguing session on GaN-Graphene hetero-junctions. Really excited to attend that one.  Apart from that we will be presenting three more posters late in the afternoon on Amit’s work on diamond, Omid’s DC-DC Converters and possibly Konstantin’s work on graphene.

I’ll be posting the conference updates (hopefully) at the end of each day of the conference.


Graphene in Press

12 09 2011

Our paper on understanding metal / graphene contacts at high temperatures has appeared in Applied Physics Letters (Vol. 99, Article number 073506). The full text can be found via the Applied Physics Letters website, but if you can’t get access, drop me an email and I can send you a copy across.

Chemical Sensors

20 04 2011

Following the gas sensor findings from a few weeks ago, where we showed that we can make an array that can discriminate between species in a mixture, rather than just the overall level, our first graphene results have landed. Whilst we wait for the gas rig to be fixed (the BOC fairy dropped off a new cylinder and we took the opportunity to install the closed loop pressure system) our graphene sensors have been tested for their sensitivity to solvents.

Graphene solvent sensitivity sensor

Room temperature sensitivity to solvents

As expected this shows a difference between polar and non polar solvents and the next step is to try this with more realistic gas conditions to understand how it can function as something like an air quality monitor. Then we need to work out how we can make an array, so it might well be back to the idea behind the SiC arrays!