My first couple months doing research have been great.  I am doing research through CEEM in Professor Palmstrom’s lab.  Professor Palmstrom focuses in the area of Thermoelectrics.  The study of Thermoelectrics focuses on the harnessing of energy from a difference in temperature.  It can be understood as a direct conversion between electrical voltage and a temperature difference.  Therefore, given a thermoelectric device, a voltage can be measured across two different terminals on the device assuming that there is a different temperature on each side of it.  The opposite case is also true, if a voltage is applied to a thermoelectric device, it will create a temperature difference between the two terminals.  This is a brief introduction to what my research group explores.

A couple months into my research now, it has been very interesting and action packed.  My understanding of semiconductor physics has gotten much better.  Doing hands-on research provides a whole different level of education and understanding that one can achieve.  I have taken classes that go into details of semiconductor physics as well as properties of different materials, but I have realized that there is only so much one can understand just by reading about or hearing professors lecture on.   I like to think of it kind of like this.  Let’s take a mango for example.  I can give you all the information the world has to offer about a mango. I can tell you what it feels like, what it tastes like, what its color is, what its chemical composition is, and so on and so forth.  But, describing all the different information on the mango to you will never be enough to give you the sensation you would get when you actually bite into a mango and what it tastes like.  Similarly, you can read about and attend lectures about whatever you are studying as much as you want, but until you get hands on experience with it, I personally feel like you have not fully experienced what there is to learn.

The image provided shows a thermoelectric sample I am currently working on. It is Gd doped InGaAs on semi-insulating InP on which I am running high temperature measurements on.  As we can see, the thin sample is placed in the middle on a plate where I can connect 4 gold filmed pins onto small gold contacts that are on the sample.  As shown, there are four pins on this device.  There are four pins on there so that a small current can passed through the device in different directions across terminals so that the resistance on it can be measured along with other vital information such as carrier concentration, hall resistivity, mobility, and conductivity from the sample.

Well, so far research has been great! I have been learning new things daily as well as figuring out new ways to analyze information I have previously learned from school.  Working hands on with different instruments as well as different thermoelectric materials has been very interesting, and I look forward to the future and being able to do research in my lab along with my group.

Also, I’d like to thank Ryan Need and Rachel Koltun for their guidance, and for being great mentors helping me throughout my research experience.

When I first heard that you could “grow” an LED or laser, I was shocked to say the least. I had never truly considered how solid state lasers were created until I got involved with research at the Center for Energy Efficient Materials (CEEM).  Once accepted to the program I found a lab to work in and was assigned a graduate student to mentor me.  The process has been very similar to an apprenticeship.  In a very short span of time I have learned how to use many different tools include a scanning electron microscope (SEM) and an atomic force microscope (AFM) and the crazy reactor they use to grow the devices with.

(XKCD)

I’ve been working with my mentor on making blue light emitting diodes (LEDs) and lasers now for a few months and it has been an amazing learning experience.  Blue is of particular importance because most white LEDs you see in flashlights or LED light bulbs in for use in homes are actually blue LEDs with a phosphor layer that makes them look white.  So in order to make good white lights, it is necessary to make good blue LEDs and lasers.

The process we use to grow these devices is called Metalorganic Chemical Vapor Deposition (MOCVD) which I know is a mouth full but typically is a machine that shoots various chemicals into a chamber for them to react and deposit material on top of a piece of sapphire.  Sapphire is nice because it has a similar structure to the material we want to grow on top, Gallium Nitride.

It’s an amazing feeling being on the inside of science helping with the progression of knowledge.  If you’re similar to me and like to read all about the latest scientific advances and all the amazing things scientists are creating then I’m sure you’ll find getting involved in research a very exciting and natural progression of this curiosity.

I had no idea how large the field of research was prior to enrolling at UCSB. I attended Mt. San Antonio College (Mt. SAC), a community college, for two years and never thought twice about the researching world. I was preoccupied with the worries of every prospective transfer student: what is my registration date? It was a nightmare getting the classes you’d need in order to transfer. Chemistry classes, for example, had only enough room for a fraction of the chemistry classes held here at UCSB! It was not uncommon to see groups of disappointed students trudging out of the classroom after the professor would proclaim, “No, you may not add this class. You may not even crash this class!”

It really surprised me to see how large some of the facilities were when I arrived at UCSB. There was a building for chemistry, engineering, materials, and other facilities that catered to a certain department’s needs. At Mt. SAC, everything was crammed into one building. I soon realized that a lot of the space in these buildings were for research efforts, and not multiple fancy classrooms!

Mt. SAC’s “Science” Building

After completing the Fall 2012 quarter, I was interested in joining research. So, I looked around on the web for a while and found some student Summer 2013 opportunities through the MRL webpage (which you should be looking at if you are an undergrad interested in materials research!). I applied to all programs available and heard back from the Partnerships for Research in Education and Materials (PREM) program UCSB had with the University of Texas at El Paso (UTEP). Right after my Spring 2013 quarter was over, I was heading over to El Paso, Texas!

My mentors/faculty sponsors were Juan Noveron and Delia Valles, an associate professor in UTEP’s Chemistry department and an associate professor in New Mexico State University’s (NMSU) Industrial Engineering department respectively. For 10 weeks, we were trying to figure ways out on how to convert biomass into usable organic solar cell materials (abstract here). Did we find out if our research efforts worked in 10 weeks? That was indeterminable by the end of the research program, and I learned that that was okay! Was it an absolute loss? No way! There was a lot I learned about research and the nature of my project. One valuable skill I picked up was learning how to read scientific documents. There was and will always be a lot of previous knowledge (I extensively used Google Scholar!) that can possibly be applicable to your own research.

UTEP’s Chemistry and Computer Science Building (where I spent my 10 weeks doing research!)

My internship ended, but that was not the end of my pursuits in research. I contacted Jon Schuller, from UCSB’s ECE department, to join his lab, where he does organic solar cell related research. While related in topic, the type of research done is different. We are trying to understand the effect a polymer’s morphology will have on its optical properties.

This pretty much sums up my experience coming in as a transfer student from a community college to joining research labs. Why didn’t I start earlier? This goes back to my earlier statement on how I was too side-tracked and focused on transferring first. Also, it was a bit of me not knowing exactly what I wanted to do! If you hadn’t known, there are REU (Research Experience for Undergraduates) and other programs community college students can apply for. I’d encourage this if you’re especially interested in the field of research!

When it comes to alternative energy, most people can quickly name off a few, for example solar energy, nuclear fission, natural gas or hydroelectric power. Hardly ever will you hear someone name thermoelectrics, but honestly, it’s for a good reason. Thermoelectrics is still very much a developing field, and recent advances in the theory of thermoelectrics has led to a huge push to advance existing thermoelectric technology.

This quarter I was introduced to thermoelectrics, including its theory, applications, and the experimental procedures of testing thermoelectric devices. The lab I am working in is mostly concerned with maximizing what is called the figure of merit. The higher the figure of merit, the more efficient a thermoelectric material is for its two main applications: power generation and cooling.

Thermoelectrics are already have seen some applications to the real world, but the figure of merit is not high enough yet in order for thermoelectrics to be applied on a large scale. Luxury vehicles with seat warmers often have thermoelectrics. This is because when you apply a potential across some thermoelectric devices, they create a heat gradient. The cold end is used to cool seats very quickly. Unfortunately, little niche applications such as these are the only real benefits they have provided us in the real world. With a higher figure of merit though, power can be recaptured at high efficiency if there is a heat gradient across the thermoelectric material. Ideally, thermoelectrics could be placed in exhaust pipes to make cars more efficient or in power plants to salvage much of the lost energy to heat.

The lab I am working in tests the conductivity, carrier concentration, Seebeck coefficient, mobility as well as other parameters that influence the figure of merit. So far I have been introduced to the entire experimental process of creating a semiconductor wafer and measuring its hall coefficient through a Van Der Pauw machine. There are several different types of Van Der Pauw machines, mostly for different temperature ranges. Van Der Pauw machines work by applying a magnetic field across the material, creating what is called the Hall Effect. From the response in magnetic field, we can measure the Hall Coefficient, as well as many other properties of the semiconductor wafer.

I’m getting really excited to progress more. A lot of what I’ve been doing has been learning experimental procedures, and while I find that very interesting I can’t wait to master the techniques and start obtaining data on a regular basis. I have learned how to perform AFM (atomic force microscopy), measure Hall coefficients, analyze and understand the types of data I am getting, as well as fully prepare semiconductor samples to be measured. It is always a little rough when you start out learning new things, but I’m confident that in a few short weeks I will start actually being very productive for the lab I am working in.

I distinctly remember the first words enthusiastically spoken from one of my professors last year prior to the start of the first lecture. “So, which of you like to cook.” Over the last several months, this seemingly non-sequitur question, directed at undergraduate students eager to learn about transistors, has started to resonate with me.

Anyone who has ever tried creating a new recipe is familiar with the wide array of sentiments associated with the cooking process. Anticipation, excitement, anguish, disappointment: all proper terms describing the whirlwind of emotions which pulse through the veins of every chef as they try to perfect the world’s next delicacy. Such chefs are also undoubtedly familiar with the extreme levels of precision and effort needed to create something truly noteworthy.

In my research project we are working on developing a novel type of transistor. Much of the difficulty in implementing this transistor stems from the complexity of the material foundations which constitute the device. Current devices we are working on often consist of around 7-10 layers of various semiconductors/alloys of different widths, purities, and doping concentrations. Even if such designs were perfect in themselves one doesn’t have to try too hard to imagine the difficulty in fabricating this device when this is done at the micrometer level (think diameter of hair).

(not our group’s transistor design, but similar in complexity. Think worlds smallest birthday cake).

As of late, I have personally been involved in testing/data analysis. My lab setup includes a microscope, a DC probe station used to connect the transistors to a power supply station, and a computer from which I am able to gather many different data characteristics. I then analyze this data using computer software and seek out data trends/comparisons to earlier devices. The testing process can lead to a contorted roller-coaster of feelings/sentiments. On one hand, I’ve seen parts of our devices develop significant improvements, which is very exciting, but there are also times when certain device components deteriorate. When I first undertook such testing tasks I became frustrated by this notion that improvements and deteriorations can happen simultaneously and unintentionally. I’ve since begun to view these occurrences as beneficial learning experiences, which we then try and equate back to earlier manipulations in our designs.

Although inherently an imperfect analogy, I believe my professor last year was fairly accurate in his comparison of transistor design/development to cooking. Both require planning, time, precision, accuracy, and an ability to accept failure and then learn from it. So, to anyone else out there considering being involved in a transistor based research project my first question to you is do you like to cook?