My name is Tiffany Wu and this is my fifth week at the University of Houston continuing my project with ellipsometry and the Arduino. This week, the Welch students (students from the other program also doing research) and us Pinhead interns had a poster session to prepare for since this week was their final week in Houston. So, most of my work was preparing my poster and finalizing any data that I could add onto it.
To start the week off, I collected some data for a piece of commercial ITO and just a plain glass microscope slide to see how the graphs would look in comparison to the silicon and gold wafers. Due to the higher transparency of the glass and substrate of the ITO film, the intensity of the voltages that were detected were much lower since the samples weren’t as reflective. I collected two sets of data for both of the samples; one that had the quarter wave plate in the path of the laser and one that did not so we could see the differences. After I had collected the data for the glass and ITO, I realized that I needed to run the samples I had used before (silicon and gold) with the QW in the path of the laser to have an accurate showing of all of my tests for my poster. So, I spent the rest of the day collecting the data for all my necessary graphs and isolated each set of data to one reference pulse to make it easier to interpret.
On Tuesday, I spent the day making my poster and compiling all of the research and data that I had gotten from past four weeks. It was a bit difficult to decide what to include and talk about, but I created a rough draft of my poster to be approved by Professor Baldelli.
Wednesday was a bit of backtracking because Professor Baldelli discovered a method to make our data fit the model properly so I had to reorganized the data I collected for all 8 trials to make it easier for him to fit it to the model and have reliable data to use for doing so. Before, we had been only using one column of the detector output with the sine graph to fit our data to the graph, with each sample having a inconsistent amplitude due to the varying reflectivity and transparency of our samples. Since each cycle of my data collection consisted of 3-4 reference pulse cycles of the analyzer drum rotation and we only needed one reference cycle, we decided to take just the detector data from the remaining cycles that we had not been using previously and plotted it onto the first cycle we had been using. By doing this, we would have 3-4 sine graphs on one reference pulse cycle. In theory, all of the intensity data should be relatively the same, so by overlapping them and finding the average, we can eliminate the small percentage of error for our calculations and fitting. This process was a bit tedious at the beginning since I had trouble finding each cycle and its relative data, but after the first couple of samples, I got the hang of it very quickly.
On Thursday, I spent the morning normalizing my data, or making it so that all of our graphs would have a maximum amplitude of 2. Since the model graph that we have been trying to get it to fit to was normalized by a degree of 2, we needed to have our data match this so we could properly compare it. For the rest of the day, I added some changes to my poster and went to go get it printed for the poster session. I also spent some time rehearsing a brief overview of my research so that I could present it.
My Poster
Friday started off with our usual weekly group meeting, where one of the graduate students presented an update on her research. Following the meeting, Saida, Katya, and I went to help set up for the poster presentations that we were going to do with all the other students. Overall, I think my presentation went very well and it was a very good opportunity to show what I have spent the past month learning about. The parents, graduate students, and professors had asked many different questions on my research, and I answered each with the knowledge that I had acquired.
Saturday was quite a sad day since it was the Welch students’ last day in Houston. My roommates checked out of the dorms in the morning and our group gathered a lecture hall for their closing event. During this, each of us had to give a five minute “elevator talk” where we were given a piece of chalk and a board to show and talk about everything we had been studying. I think my presentation went fairly well and it was a nice way to learn more about what the other students had been researching. Finally, me and Saida said our goodbyes to our fellow group mates as they all left to head back home. It was sad to see them go, they were all such amazing and kind people that I really enjoyed spending time and living with this summer.
Group Photo With the Welch Students, Professor Baldelli, and our RA
My time in Houston is also coming to an end and time has really flown by while I’ve been here. This next week, I am going to be measuring some of the ITO films Saida has produced and making a manual for my program so that the lab can continue to use it for their research and analysis.
Tiffany, it sounds like you have had some incredible experiences over these last couple of weeks! I am glad to hear that your presentation went well and I can’t wait to read about your last bit of time in Houston.