One-on-one with Utkarsh Jadli

PhD student at the Queensland Micro Nanotechnology Centre

As a PhD scholar at the Queensland Micro Nanotechnology Centre (QMNC), Utkarsh Jadli strives to develop the next generation of Gallium Nitride (GaN) transistors for power circuits. He spoke to IMCRC about his research.

Q: What is your background, and what led you to take up a PhD position for this project?

I studied Electrical & Electronics Engineering back in India, which allowed me to follow my passion for innovation. In my final year at university, as part of a research project about ‘Solar Powered Air Conditioning for Medical Applications’, I learned what research and development really means, the challenges it involves, and how it can impact society. Hocked on research and interested in electronic simulations, models and design, I continued to do a Master by Research in Control Systems. The first paper I wrote as part of my Master’s program was on solar engineering. I modelled a solar panel by estimating its parameters to enhance its power delivering capacity.

My analytical, research, and communication skills, paired with my curiosity and passion for learning new things, then led me to pursue a PhD in Electronic Engineering. While researching PhD positions, I came across this project called Gallium Nitride High Electron Mobility Transistors (AlGaN/GaN HEMTs). As an undergraduate of Engineering, I knew about basic transistors such as bipolar junction and field-effect transistors (BJTs & MOSFETs). The name AlGaN/GaN HEMTs, however, caught my attention. I started looking into the topic and found out that AlGaN/GaN HEMTs are far better compared to their silicon-based (Si) counterparts and that they are regarded as the future of semiconductors devices. Thus, I decided to apply for the PhD position and join this futuristic venture.

Q: Tell me a bit about the project, and what is your role in it?

With increased electricity demands and a growing interest in renewable energy technologies, enabling technologies such as power electronics are becoming more and more important. The progress of power electronic systems is driven by advancements in power semiconductor devices. As the power electronics market continues to grow, it is becoming increasingly important to select the appropriate and most efficient power semiconductor for a given application.

Unfortunately, Si-based power devices are unable to meet today’s high-performance requirements. This has led to an intensified research in wide-bandgap devices such as AlGaN/GaN HEMTs which have higher breakdown voltage, bandwidth, mobility, and thermal conductivity. These exceptional features make AlGaN/GaN HEMTs a desirable power device for high frequency and high-power applications.

Despite these remarkable properties, AlGaN/GaN HEMTs suffer a major disadvantage i.e. they are normally ON devices and therefore not fail-safe. Due to this limitation, they have limited market potential.

This research project focuses on developing a cost-effective normally OFF AlGaN/GaN HEMTs. In collaboration with clean technology company BluGlass, supported by IMCRC, the QMNC aims to:

• Successfully manufacture a cost effective normally-Off AlGaN/GaN HEMT
• Benchmark commercially manufactured HEMT devices – ON and OFF, characterise their performance to better understand the application of these devices in power circuits and then do a SWOT analysis that should lead to recommendations how to customise the manufacturing of AlGaN/GaN HEMTs for particular applications. (My part of the project)

Q: How do you think your part in the project benefit manufacturing?

Manufacturing of more efficient power-conversion systems requires better design. The project provides new insights into the advantage of AlGaN/GaN HEMTs over traditional transistor (Si and SiC MOSFETs) due to reduced power dissipation by the significantly reduced parasitic capacitances. Also, manufacturers of AlGaN/GaN wafers and HEMTs can use this knowledge to optimise their devices for specific applications (an example of concurrent engineering).

Q: What do you like most about the research and your PhD?

In general, research has its challenges, but at the same time, it offers lots of opportunities to learn something new. I enjoy those research challenges and I try to embrace them to progress and deliver on the project milestones assigned to me as well as advance my personal capabilities

My supervisors are very good at what they do and very supportive. Despite the research being challenging, my PhD has been an enjoyable and rewarding experience so far. I also enjoy sharing my knowledge with other students and the wider research community.

Q: How do you feel about an industry-led research project?

Industry-led projects offer you unique and diverse scenarios to apply your theoretical knowledge. That is another reason for me joining this project  – to solve a real-life business problem as part of my PhD. Also, industry-led projects have a defined goal and a set time duration which keeps you focused. Another good thing about industry-led projects is that we can access state-of-the-art equipment which is not often available to universities.

Q: What do you see yourself doing after completing the PhD?

Once the project is completed, I would like to continue working in this field, potentially as a Post-Doc. Developing a product is one thing, but successfully commercialising it is another.

Climate change is a real threat and requires great attention as well as innovative energy solutions. Not only must we stop using non-renewable energy sources, but adopt more renewable energy sources. Hence, once the project is completed, I would like to work with industry, focusing on renewable energy solutions. I strongly believe that the developed AlGaN/GaN HEMTs will be the key to the future of the more efficient renewable energy systems.