August 21, 2013

Ahhhhhhhhhhhh! I cannot believe that it is week nine of the UCLEADS program! My fellow UCLEADS colleagues and I have only one week left. This experience has taught me various things, ranging from determining the type of lab environment/culture I want to work under to the graduate school application process.

To begin with, the most important realization I made in the Szumlinski Lab was that regardless of where I end up pursing a higher degree, I would like to work in a collaborative setting where there exists many interactions with my fellow research colleagues. Having seen in less collaborative settings, I really appreciate that in the Szumlinski lab, the professor, the graduate students, and lab technicians were open about their personal life which I appreciated, especially their transparency. In other words, I would like to be in a work environment where there is a balance between both one’s personal and professional life.

In regards to the UCLEADS/Eureka/ CEEM events, I noticed some common themes throughout the seminars and talks like the importance of networking, taking advantage of all the opportunities offered, keeping an open-mind, and time management skills.  Actually, my favorite seminar was our last one which consisted of a panel of faculty members who shared their journey. There were a total of three professors: a computer scientist, an engineer, and a biologist. A very diverse panel! And I had the opportunity to ask two questions: “What is one thing you wish you knew as an undergraduate applying to graduate school?” and “Besides establishing a good relationship with your mentor, what are three factors to take into consideration when applying to or deciding on a graduate program?”

One of the challenges I faced with the program was the bi-weekly powerpoint presentations. Let’s just say… I have refined my public speaking skills since then! Although I found it difficult to present, I enjoyed it at the same time because I had the opportunity to hone my skills in preparation for my final talk and the UCLEADS Symposium. It was definitely a love-hate relationship! I would say one of my favorite events was the poster session. I felt satisfied with my end product (poster) and a lot more comfortable talking about my project. Funny story: I was actually surprised by my parents and siblings before my poster session. I had invited my parents the night before and was not expecting anything from them since I understood that my dad had a very tight work schedule. My father assured me that they were not going to be able to make it because he has a lot of work and that his car was having some problems, blah blah, blah. You know parent’s stuff! However, he said this intentionally to mess with me! Long story short, my family surprised me, and I was completely speechless. Despite a language barrier (because they primarily speak Spanish and very little English) they managed to show up to demonstrate their unconditional love and support. To be honest, I do not think they understood why I was doing what I was doing in lab, but I did not expect them to. I simply appreciated and cherished their presence. In addition, my mentor and professor also attended which made me feel great and loved. At the end of such a successful day, I was a happy camper!

Knowing that the end of the program is near, I feel like I have not only grown on a professional but a personal level. Being surrounded by motivated STEM students, I feel determined to apply to different professional societies and attend out-of-state conferences to present my research. I am dying of thirst to create opportunities for myself and open new doors while keeping an open-mind. Furthermore, I was inspired by a fond friend of mine, who is the co-founder and president of UCSB’s oSTEM club, to start up a club in Davis where both the LGBT (& allies) and STEM communities come together. I find this to be a great opportunity to bring diversity to my home-campus and am very excited to give this a try!

To all those of you who are high school students going to college or if you are a first or second year college student, I strongly recommend you apply to any of the research programs offered at your college. I can guarantee you that you will grow in many ways!

To conclude, I would like to take the time and thank my mentor, Sierra, for all her patience, time, support, and dedication. I appreciate her not only as a mentor but most importantly as a friend. I feel fortunate to have a mentor who shares a similar mentality which allowed us to connect on a deeper level.  Thank you for all the advise and deep conversations about life! Dr. Karen Szumlinski, again, I am so thankful to you for giving me such a great opportunity to work in your lab. I can honestly say that I leave the lab with some lifetime friendships. Thank you for opening your doors to me! Finally, I would like to thank the first two individuals I met from the lab, Christina and Megan. Right from the beginning these girls made me feel included and comfortable. From the smallest things, like inviting me to go grab a cup of coffee to getting invited to going kayaking and Megan’s going-away lab dinner. You girls made me feel welcomed and for that I will always be thankful!

Thank you everyone in Szumlinski’s and Kippin’s lab that made this a fun and memorable experience!

I had quite a lot of expectations for this summer and they were all met, thanks by the wonderful people who run UC LEADS. So let me tell you some of them.

One of the reasons why I chose to do semiconductor research was to get a bit more lab-technique experience. I believe that it may due to me being close to graduating soon, but that can vary by major. I learned how to use atomic force microscopy (AFM), Nomarski imaging microscopy, how to measure semiconductor properties, honed some of my soldering skills, and many other lab techniques. The other thing that was incredibly satisfying was the project results!

My project focused on growing indium arsenide (InAs) on a gallium arsenide (GaAs) substrate for use of devices such as hard drives. The issue of InAs on GaAs is that the surface of InAs is usually rough and that causes a drop in semiconductor performance. Roughness comes from dangling GaAs atoms (referred as dislocations) that remain unconnected to the InAs atoms due to straining that the InAs layer experiences. This is due to mismatch of the lattice constants of InAs and GaAs of 6.1 Å and 5.6 Å, respectively. A simple way to say it, the gallium and arsenide atoms have more compact spacing than the atoms in the indium arsenide layer. This mismatch forces the InAs to strain, which eventually leads to defects and roughness. Since this type of straining depends on thickness of the InAs layer, we grew InAs with different thicknesses (this was done on a 500 nm GaAs buffer plus substrate). After we grew these samples, I took them to take AFM images and to measure their transport properties.

From left to right, the growth thickness of indium arsenide: 50 nm, 100 nm, 250 nm, and 500 nm

Those holes you see are the dislocations, which decrease in number as thickness increases. This will mean that semiconductor performance (measured by the electron mobility, which tells you how fast the conducting electrons are moving through the semiconductor) will increase. The question is, though, is the relationship between growth thickness and electron mobility. Below was surprising (to me, at least!):

Indium arsenide on gallium arsenide performance as a function of indium arsenide thickness

I (again, only speaking for myself!) did not expect it to be non-linear. Basically – in this case – the electron mobility doesn’t get much higher as thickness increases. I find it fantastic to find results such as these, especially since it can be used by members in the lab. This result made it great summer experience.

One of excellent suggestions that my mentor (Borzoyeh Shojaei) one that I will also recommend. If this is your second (or third, or fourth, etc.) lab, speak to your previous professors. It shows them your new skills, exciting results, and it will show them how much you developed ever since. This will indeed make it easier for them to recommend for other positions in their labs, in other people’s labs, in work, and in graduate school. You’ll surprise yourself how much you’ve changed too!

Hard hats, particle accelerators, electron guns, lasers, orange goggles, and a PhD thesis…So much has happened these last few weeks in the Sherwin lab! Here is a brief play-by-play of the most recent exciting events in my lab this summer:

The Chronicles of the Free Electron Laser:

The very powerful Free Electron Laser (FEL) we use for various experiments in terahertz spectroscopy had a little hiccup. Simply put, the particle accelerator had to be opened and serviced by our FEL “master” and mechanic, Dave. In order to do this, the entire accelerator must first be drained of the sulfur hexafluoride gas that fills it. Once the accelerator cavity is cleared, people can safely go inside. Dave kindly gave me and a couple of my lab-mates an up-close and personal tour of the all-powerful FEL. Here is the hole in which I bravely crawled through to get inside:

Upon entering, the floor on which you stand also serves as an elevator shaft, taking you up or down based on what section of the accelerator you wish to see. Here is what looking up the accelerator from the inside looks like:

Simply put, the key components of transporting and “accelerating” electrons lies within this center structure. Within this structure is something called an electron gun, which essentially shoots out an electron beam. Here is the electron gun (located at the top of the accelerator):

After learning an incredible amount about how the main components within this structure work, one by one everyone in the accelerator crawled out. Here I am with one of the grad students in the Sherwin lab, Jessica. We were both so thrilled to have been inside such an amazing part of the FEL!

Orange Goggles:

Last week the CSEP summer internships held the annual poster session. This year another intern in my lab, Jordan, was also a part of this presentation through the INSET program. In order to more effectively convey the great, fun, exciting, and innovative research that goes on the Sherwin lab, Jordan and I teamed forces and presented our posters side-by-side. Both eager to share our most recent summer project findings, we needed to find a way to draw in a big crowd. In other words, we needed a way to hook spectators’ attention. So we grabbed a couple pairs of laser safety goggles (orange!) and wore them while standing in front of our respective posters:

The glasses really complemented our posters (and they are very sleek and stylish)! In the end we had a great turnout of people – people from all fields of science, and also many who weren’t in science at all! Being able to explain my project, over and over again to a new person each time, never tires or bores me. I’m always ready and excited to talk about my work (next time you see me, don’t hesitate to ask me anything about my research!). All in all, the poster session was a great success.

Submitting the PhD thesis:

Okay, so I didn’t submit a PhD thesis (I’m still an undergrad!). But my mentor, Devin, just did; congratulations Devin! Devin has been my mentor for the past year – last summer, last school year, and this summer. Here we are last summer (2012), in the magnet lab:

Devin’s been an awesome mentor – always making sure I understand the fundamental concepts behind our research and encouraging me throughout the summer. He, along with Dr. Sherwin and the entire lab, has made my research experience a fun, challenging, and memorable one. An important theme I’ve learned here is that research is a collaborative effort – between PIs, post-docs, grad students, undergrads, etc. Whenever I run across a difficult problem, Devin or any of the other people in my lab are always eager and happy to help.

Even though UC LEADS is coming to an end for the summer, I will still be working in the lab. New material for the terahertz light absorbers I’m making just came in – I have a good amount of work ahead of me, and I can’t wait. This is not the end, it’s a new beginning!

Nanowires, nanoparticles, devices, oh my! Time has gone by so fast and I cannot believe we are already so close to the end of the summer internship. I have learned so much in such a short amount of time and, although there is still a tremendous amount for me to learn, I am thrilled to be experiencing so much!

It feels like we have accomplished so much since my last blog post! We have managed to experiment with gold nanoparticle deposition onto our nanowires (something we weren’t sure how well it would work), which was pretty awesome, I must say. Jose had me figure out and organize our procedure for the gold nanoparticle deposition. Although it was hard, it really pushed me to understand what we were doing. It is really hard to imagine all the possibilities for things to go wrong, as there are so many! Though it can be difficult sometimes, in the end I like it when Jose pushes me to figure out things on my own. I am forced to ask more questions and dwell deeper into our research, inevitably learning more.

By now we have successfully finished our devices, and just need to start testing them. This has proven to be hard. But research, just like life, would not be half as awesome if there were no challenges. Nor can I imagine a problem we could not solve with some time and effort, especially with such great minds in our lab. With that, our eventual success will only taste that much sweeter once we have reached it.

In addition to the research I have done with Jose, I have also been able to work a bit with Brian Evanko, another graduate student working as a part of the Moskovits Lab. He’s working on trying to deposit copper (I) sulfide electrochemically for use in photovoltaics. This was a nice change; particularly because there was more chemistry involved than Jose’s and my project (don’t get me wrong, I love our project to death). It was nice to again be in my element. It was also nice just to work with other people in our lab because of the variety in the research as well as the friendliness of everyone. However, I am glad to be focusing again on my project with Jose.

I cannot get over some of the things we have done. Every SEM (scanning electron microscope; look it up if you don’t know about it, it is awesome) image of ours brings me so much pride. I would have never even fathomed any of this when I was younger. I am pretty sure I thought the splinters in my fingers were the smallest things possible. This is incredible. I mean 10 nm? Amazing!

Seven weeks in and research I am not going anywhere. You are too cool, so bring it on. I cannot wait to see the outcomes of our project; every step we take is another towards knowledge. We may have a long journey ahead still but what a remarkable story.