Wide Bandgap (WBG) semiconductor materials have gained significant attention in recent years, particularly in power and RF electronics, due to their ability to operate at much higher power levels.

Gaurav Mukherjee, our next pathbreaker, GaN Process Development Engineer at X-FAB (Dresden, Germany), develops manufacturing processes for GaN-based power devices that are efficient, compact, and reliable.

Gaurav talks to Shyam Krishnamurthy from The Interview Portal about pursuing his BTech in Mechanical Engineering followed by a Masters and PhD in Semiconductor Physics focused on subjects like solid-state physics, quantum technology, and laser physics.

For students, have a clear vision, the motivation and discipline to back it up. Don’t fear taking risks — that’s where growth is made and purpose is found.

Gaurav, can you share your background with our young readers?

I was born and raised in New Delhi, where I also completed my high school and senior secondary education. I was always curious about how things work, especially in the world of technology, so I knew early on that I wanted to become an engineer.

Back in 2013, when I was applying for college, I wasn’t sure which branch of engineering to choose. There was a lot of focus on preparing for entrance exams, but not much guidance on selecting the right branch based on one’s interests. At that time, mechanical engineering was seen as a reliable and “evergreen” field, offering a wide range of job opportunities. So, I decided to go for it.

Once I got into the course, I discovered that I really enjoyed the subjects we studied. I was fascinated by things like:

  • Fluid Mechanics – which explains how liquids and gases move, and how machines like pumps and turbines work.
  • Thermodynamics and Heat Transfer – learning how engines produce energy and how heat flows in different systems.
  • Strength of Materials – which helps understand how parts in machines handle force and pressure.
  • Material Science – the study of different kinds of materials like metals, semiconductors and crystals, and their properties.

These topics sparked my interest, and I realized I wanted to go deeper. That’s why I decided to do a master’s degree in Physics later on.

During college, I was also part of the badminton team, which helped me keep a good balance between studies and fun. My father worked as a manager in an HVAC company (heating and cooling systems), and my mother was a homemaker. In 2018, after completing all the necessary steps, I started my master’s journey in Physics at a university in Germany.

What did you do for graduation / post-graduation?

I completed my Bachelor’s in Mechanical Engineering from Pune, India. Driven by a growing interest in fundamental sciences, I pursued a Master’s degree in Physics, which deepened my passion for research and ultimately led me to a PhD in Semiconductor Physics. He pursued both his masters and PhD from The Philipp University of Marburg.

I did not get scholarship but had some savings which helped me initiate the process. Furthermore, to support my living costs for 2 years, I took credit from a bank.

What were some of the key influences that led you to such an offbeat, unconventional, and unique career in Semiconductor Physics?

a) Key Influencers:
Books like The Theory of Everything, Feynman’s lectures on Physics, The Tao of Physics, and video lectures from Walter Lewin (MIT), Stanford, Yale, and Penn on solid-state physics deeply inspired me. Platforms like NPTEL and MIT OpenCourseware helped solidify my interest.

b) People & Mentors:
Friends from my undergraduate days, work colleagues, a college professor, and seniors pursuing research in nuclear physics were instrumental in encouraging me to explore this path.

c) Turning Points:
My third year in engineering, my first job, and the completion of my Master’s degree were all pivotal moments that shaped my decision to transition toward applied physics and semiconductors.

How did you make a transition to a new career? Tell us about your career path.

During my BTech, I developed a strong interest in applied physics. By my third year, I began preparing for the GATE exam, a highly competitive entrance test for engineering graduates in India. I cleared the exam and secured admission into a prestigious integrated Master’s and PhD program. However, due to unforeseen administrative hurdles, I began working as a technical sales engineer supporting industrial pumps, a role aligned with my engineering background.

My passion for semiconductors continued to grow, and I made the decision to pursue a Master’s in Physics in Germany. I handled all the application and visa processes independently and was accepted into a university where I focused on subjects like solid-state physics, quantum technology, and laser physics. My final-year research centered on modelling semiconductor lasers for telecom.

During my Master’s research, I worked on modelling ternary III-V semiconductor lasers with a specialized layer geometry designed to minimize optical transmission losses. In the field of optoelectronics and data transmission, reducing losses is crucial, especially in the 1.3 – 1.6 micron wavelength range, where fiber optic transmission experiences minimal attenuation. By integrating a tailored combination of III-V alloys into a carefully optimized structure, the design aimed to target this low-loss window. Ternary III-V semiconductor lasers utilize semiconductor alloys formed from three elements, where two are from Group III and one from Group V.

My focus was on modelling the laser geometry—such as layer thicknesses, optical mode confinement, and refractive index profiles—to assess the feasibility of achieving efficient emission in this wavelength range. This work contributed to understanding how material composition and structural design impact the performance of III-V-based optoelectronic devices.

After earning my Master’s in 2020, I went on to pursue a PhD focused on MOVPE growth and characterization of semiconductor materials for optoelectronic applications.

My PhD research focused on overcoming limitations in existing semiconductor alloys by enabling the monolithic integration of III-V lasers and solar cells on CMOS-compatible silicon substrates. While significant progress has been made in growing III-V semiconductors on engineered substrates—such as offcut wafers or non-conventional lattice planes—my work specifically targeted integration on standard CMOS Si substrates to streamline industrial fabrication processes.

From a material perspective, the novel alloy systems I investigated hold the potential to enhance the efficiency of current telecom laser technologies. Additionally, they open new avenues for research into scalable techniques for monolithic III-V/Si integration.

How did you get your first break?

Receiving an offer to pursue a Master’s in Germany was a major turning point. I applied to 18 universities but only got accepted into two due to the difference in academic backgrounds (Engineering vs. Physics). That breakthrough was life-changing.

Ever since completing my engineering degree, I have been deeply committed to strengthening my understanding of semiconductor theory and its applications. I read several foundational and advanced books in the field to broaden my knowledge base. Additionally, I enrolled in semiconductor physics courses on Coursera—not for credentials, but as a way to internally evaluate my grasp of the concepts and assess whether I truly had the aptitude for this field.

This self-driven preparation paid off. When I was interviewed for my master’s program, I was able to clearly and confidently convey both my motivation and understanding, which significantly strengthened my application.

Securing an industry position after a PhD was a challenging journey. One of the first things I had to accept was that rejections are a natural part of the process and do not reflect a deficiency in my knowledge or capabilities. During my job search, the semiconductor industry itself was going through a downturn, which added to the difficulty. After completing my PhD, I took a month to reset and mentally prepare for the job hunt. I applied to around 20–30 positions, was invited to five interviews, and ultimately received two offers. This entire process spanned about four months. The most valuable lesson I learned during this period is that discipline always outweighs motivation. There were days when rejections hit hard and my motivation dropped to zero—I didn’t feel like applying for jobs or learning anything new. But my long-term vision kept me grounded. Even when motivation faltered, discipline carried me through. In the end, the sense of achievement was incredibly rewarding.

What were some of the challenges you faced? How did you address them?

Challenge 1: Academic Background Mismatch
Switching from Mechanical Engineering to Physics was tough, especially since most German universities require a Physics undergraduate background. Patience and persistence helped me overcome rejections.

Challenge 2: Preparation & Logistics
Balancing job responsibilities with IELTS prep, documentation, and visa procedures was demanding. Staying focused on my long-term goal kept me motivated.

Challenge 3: Language Barrier
Learning German quickly through a crash course while managing everything else required effective time management and grit.

Where do you work now? What problems do you solve?

I currently work as a GaN Process Development Engineer at X-FAB in Dresden.

I develop manufacturing processes for GaN-based power devices that are efficient, compact, and reliable.

Gallium Nitride (GaN) is a wide bandgap (WBG) semiconductor that has gained significant attention in recent years, particularly in power and RF electronics. Its wide bandgap enables a much higher breakdown voltage compared to silicon (Si), which has been the backbone of transistor technology for decades. In fact, GaN can offer up to 10 times the breakdown voltage of Si, allowing devices to operate at much higher power levels.

In addition to its superior power-handling capabilities, GaN also exhibits faster switching speeds due to its intrinsic material properties. One of its most compelling advantages is the ability to fabricate high electron mobility transistors (HEMTs) without the need for intentional doping. The HEMT structure naturally forms a channel of free and highly mobile electrons, resulting in a carrier density more than two orders of magnitude higher than that of silicon-based devices.

These are just a few of the many advantages GaN and other WBG materials offer over conventional silicon. In this fast-evolving landscape, my role is a strategic one, contributing to the development and optimization of GaN-based technologies for next-generation applications.

What skills are required for your role? How did you acquire them?

Key skills include semiconductor physics, process design, device optimization, SPC, DoE, and data analysis using MATLAB, Python, and Minitab.

  • My role involves researching innovations, evaluating market trends, developing novel processes, and managing R&D projects.
  • What I love most is the continuous learning — every day presents a new technical challenge and the opportunity to contribute meaningfully to fast-growing technologies.

How does your work benefit society?

Our work contributes to:

  • Energy-efficient electronics (phones, computers)
  • Green energy applications (solar, EVs)
  • Fast communication (5G, data centers)
  • Sustainable transportation (EV inverters)
  • Space technologies (satellite and payload systems)

Tell us an example of a specific memorable work you did that is very close to you!

Publishing my first research article and filing a patent on a novel semiconductor measurement technique stand out as deeply fulfilling moments.

Your advice to students based on your experience?

Have a clear vision, the motivation and discipline to back it up. Don’t fear taking risks — that’s where growth is made and purpose is found. Learn from mistakes and keep believing in yourself. I never imagined I’d pursue a PhD in Physics abroad, but faith, perseverance, and good company made it possible.

Future Plans?

Continue growing in the semiconductor industry, sharpen my project management skills, and become multilingual (German, Mandarin). On a personal note, I aim to travel extensively and experience diverse cultures.