CHTM Postdoctoral Student Emma Renteria Graduates

March 8, 2018 - CHTM

Emma Renteria

Emma Renteria

Emma Renteria, a recent UNM graduate and CHTM doctoral student, graduated Fall 2017. Her dissertation was entitled, ‘Integration of Thin Film TPV Cells to CVD Diamond Heat Spreaders. To see more about her work, you can read her research profile here.

 Now, she is a Post Doctoral Fellow working with Professor Ganesh Balakrishnan’s Optoelectronics Research Group, which specializes in compound semiconductors with a focus on high power lasers, solar cells, and novel nano-structures. 

Freestanding thin film narrow bandgap InGaAs solar cells

Some of her recent work with the Optoelectronics Research Group involves Freestanding thin film narrow bandgap InGaAs solar cells. She’ll be presenting this research at the MRS Spring 2018 meeting in Phoenix, Arizona.

Freestanding thin film InGaAs solar cells had been demonstrated for the first time.  Having freestanding thin film solar cells of different bandgaps could be of great benefit for the demonstration of spectrum splitting solar cells.  InGaAs, with a In/Ga ratio of 0.53/0.47, is lattice-matched to InP and it has a bandgap of 0.75 eV corresponding to a cut-off wavelength of 1.65 µm.  Hence, InGaAs cells are great absorbers in the near infrared part of the spectrum.  Figure 4 (a) shows that the performance of the thin film InGaAs cell is as good as the performance of the InGaAs cell on the substrate.  The process developed to achieve freestanding thin film InGaAs cells is highly reproducible and can produce a high yield in a single batch as shown in Figure 4 (b).

                                                                Freestanding Thin Film

Figure 4: (a) Current density – voltage characteristics of thick and thin InGaAs solar cells under AM1.5G illumination and (b) yield of freestanding thin film InGaAs cells


We wanted to highlight her achievements and ask her what her experience has been and why she has decided to stay at UNM and CHTM!

What were your expectations when you started at CHTM? Did they change, and how?

“When I came to CHTM, I was an undergraduate student looking for a research internship to build up my resume.  When Dr. Balakrishnan, my advisor, showed me the cleanroom and the molecular beam epitaxy lab I was thrilled with the possibility to work here.  The opportunity that I got at CHTM was beyond what I expected.  I always wanted to work with semiconductors and fabricating and learning about the different optoelectronic devices was a delight for me. Hence, after receiving my Bachelors in chemical engineering, I decided to stay and pursue a PhD in electrical engineering.”

Do you think CHTM provided enough support for you during and after your PhD?

“CHTM definitely provided all the support I needed to complete my PhD. CHTM has a great support team.  When problems came up in the cleanroom, Douglas and Steve were always there to fix them. Tamara was always available to help me place orders or send faxes and Jessica always helped me to book for conferences even in short notice.  Everybody is friendly and helpful and of course, I am forever grateful for the support and guidance I received from Dr. Balakrishnan.”

Can you name 3 things that CHTM contributed positively to your life as a student?

“Having classes at CHTM was very helpful. CHTM is a friendly community, and being part of the QESST ERC and doing outreach with Stefi Weisburd.”

What would you tell a student that wants to start their graduate studies at CHTM? What advice would you give them?

"I would tell them that they made a great choice that CHTM is a great research facility and that there are many different interesting and challenging projects. I would advise them to interact with their peers as they can be their future collaborators and talking to people always leads to better ideas. "

Do you feel UNM and CHTM prepared you for life after being a student?

"Yes.  Since I came to CHTM, I have improved my writing, communication, and presentation skills as I had the opportunity to present my work in numerous national conferences.  I have learned how to design and conduct experiments to solve problems.  Also, I had the opportunity to mentor many high school and undergraduate students which has help me relearn the material and work on my teaching skills. I think all this has prepare me well for a career in research and development."

What made you decide to continue your career at CHTM?

"CHTM is a great place to work at.  I decided to stay because there is a lot more that I can learn and contribute while I decide if academia is the right fit for me."