First MoS2 results

28 01 2013

This is the first of the spectra from our MoS2 experiment last week. Having peeled our layer until it was only just visible, we transferred it over on to a SiO2 covered wafer and after a quick look under the microscope we went to our Raman system. The microscope image is the inset to the image, showing the flakes we examined with Raman. The spectra shown in for the large flake in the upper centre of the image

Raman MoS2 spectra

Raman Spectra of a MoS2 flake

The peak shape is interesting, unlike previously published results, we see a higher intensity for the A1g peak in comparison to the E1g peak. As an example, the left hand hand inset is from S. Najmaei et al, (Applied Physics Letters, 100, 013106). Their work details the expected separation between the two Raman peaks and enables the determination of the number of layers. Our separation of 25.6cm-1 indicates that we have bulk material, so it would appear that in addition to enhancing the lateral dimensions of the flakes, we need to continue peeling for longer!

Annual Research Conference – The Highlights

28 01 2013

Last weeks internal research conference was a great success. Not only was it the first time that I haven’t been dragged into the organisation, but we made a good job of winning the prizes …

Sandip narrowly beat Neal to the poster prize with his work on the development of gas sensor arrays, following on from Ben Furnival.

SiC gas array high temperature

The winning poster

Neal took second with his work on amplifier structures for hostile environments, an area which will support a lot of our other work in sensor development.

SiC amplifier hostile environment

SiC Amplifier structures

On top of this, Lucy won the best presentation award, beating Karthik into second place. Her presentation used Prezi, which was something new to me and judging by the comments in the audience was new to most of us. She then went on to win the second best paper prize, making it a good day out for us all.

Another year ends

30 12 2012

What a year 2012 turned out to be. Ben took the big step and didn’t just write his thesis, he then passed his viva and in the run up to Christmas got his pass list as well.

Thesis completed Ben Furnival

Ben’s completed thesis

That makes it 10 students completed so far and with Hassan finishing his corrections (number 11), that suggests that Amit will be number 12 when he finishes the last of the suggested comments and submits sometime in January.

In November I went to the IEEE Sensors conference in Taipei. Despite the perpetual rain (just like Newcastle but around 20 degrees warmer) and we got the chance for a trip to the top of Taipei 101. Unfortunately, it was dark by then and in the rain, the view was a bit muted. On the other hand, 400 engineers trying to view the damper ball at the top of the tower was well worth the trip!

Taipei 101 IEEE Sensors

View of Taipei 101

All three of our papers made it in this year, which is a massive achievement. This was enhanced when our paper on the effect of functionalisation on the performance of graphene sensors was voted the best paper in the ‘Gas and Chemical Sensors’ track and shortlisted for the overall first prize. We have also been invited to submit a more comprehensive version of the work to their ‘Best of IEEE Sensors 2012’ publication

graphene sensor IEEE solvent

Top billing for the Graphene Sensors talks

Loads more happened in 2012, including a really exciting development with the British Science Festival, so more soon!

National Microelectronics Institute

16 04 2012

Just finished my talk for tomorrows day out at the Manufacturing Technology Centre, hosted by the National Microelectronics Institute. It’s an opportunity to talk about the work we have been undertaking in power electronics using Silicon Carbide. It’s certainly interesting how rapid the change has been in this field, with efficiencies of over 95% now being reported. Our work is in the idea of novel topologies and gate drive circuits to enable SiC to move forward. Some of this work was presented by Omid at the PECI conference last month and won him the best paper award, so this is obviously a topical area! The presentation I am giving can be downloaded from here.

NMI Talk – 17th April 2012

Power Electronics Conference

16 09 2011

Whilst the team are out in Cleveland showing the world our achievements, the rest of us back here in a damp Newcastle are continuing our push to hit more of the big conferences. This week sees the abstract deadline for the Power Electronics, Machines and Drives conference, which is to be held in Bristol in March. Omid is putting the finishing touches to his abstracts, one of which describes the first demonstration of an all silicon carbide Pulse Width Modulator gate drive circuit. This circuit allows us to control the duty cycle across the entire range and we are currently using it to drive a power FET in a DC-DC converter. We will find out on the 4th of November if we have been successful, so here’s hoping!

The next outing for our resilient technology work is going to be for the new first years during induction week. A new idea is to show the new students how what they are going to learn in the first couple of years of their degree is going to be driven by our research and how they are going to help shape the world when they leave. This should be great fun and will mean that we can find the old demos, such as the flame thrower!

SiC high temperature test flame

Silicon Carbide electronics under extreme testing

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.



12 09 2011

This starts in earnest this morning, in the Renaissance Cleveland Hotel. Three of the team have made the long journey to the conference, carrying ten posters between them. Kartheek has promised to blog from the conference, so hopefully we will be kept up to date with the happenings from out there. For people who are interested in our work, our posters are uploaded here and hopefully the papers will follow once they have been reviewed.

Posters presented on Monday 12th of September 2011

MoP17; MoP21; MoP47; MoP57

Posters presented on Tuesday 13th of September 2011

TuP14; TuP46

Posters presented on Wednesday 14th of September 2011

WeP1; WeP26; WeP39