I've been meaning to post here on the forum more often, but haven't really had the mental resources available to do so for a while. Now that a pretty significant burden is off my back though, I think it's about time! Earlier today I defended my dissertation, which means that at this point I've all but completed[1] my PhD. Unfortunately I can't get into a lot of the details of my work without doxxing myself, but it's kind of a mix of electrical engineering and materials science. I've been working on the identifcation and suppression of atomic-level defects in a semiconducting oxide material to improve its electrical properties, particularly using optical spectroscopy techniques and plasma treatments. I'm not sure how much any of that would mean to most people, but I'm happy to talk about it a little more if anyone would like to know more.
ETA: I'm happy to answer questions about the work itself, the dissertation/defense process, or just the experience of doing a doctorate in general, whatever people might want to know!
There's some minor paperwork to be done and I need to submit the final version of my thesis for the university to publish, but those are both complete non-issues that will take minimal effort to do. ↩︎
i've heard "defense" a fair bit in this context, but never got around to looking up what exactly that involves. it sounds intense! how did that process work for you?
I was a bit anxious at first (always am when presenting things), but it was actually fairly chill overall. My nerves settled down after a few minutes, and when we got to the presenting portion it was more of a discussion than it was an exam. They asked some questions about my work to clarify their own understanding of what I'd done and suggested a few possible things to consider as potential future work on the project. It wasn't particularly adversarial in my case, which I think(?) is pretty much the norm. By the time you get to the point where you're writing a thesis and defending a dissertation, it's kind of all but guaranteed you'll get the PhD. People don't really fail at that point in the process.
Re: doxx avoidance, if there's anything in any questions that I can't answer, I'll just say as much. Feel free to ask whatever you'd like!
This has also been my experience both times - really, it's more a formality than anything; the only cases in which you'd be in serious trouble of failing would be if you fail to do due diligence or if there is some glaring error that somehow made it to the final paper. Which I know has happened according to my thesis advisors.
Basically - the way it was explained to me in Master's was "this is less an exam and more an academic conversation you get to lead".
ohhh, neat! it makes sense that it's sort of a "victory lap", the term "defense" just always mentally implies to me there's something to defend from.
research question! how much did you get to work with the hardware and devices used to identify the defects and suppress them? and are there any devices in particular you can talk about that are used for that? plasma treatments sounds very sci-fi
Whoa congratulations Medusa, that must have been very stressful, i hope you will be able to recover a bit and also have fun celebrating your achievement :)
Other than that, what would be a fun think you have learned and would like to share?
I (almost) always enjoy learning new and interesting things.
I conducted most of the measurements myself. I got to do a little bit of X-ray photoelectron spectroscopy XPS and mainly used luminescence spectroscopy techniques like photoluminescence. The plasma chamber we have isn't anything special as plasmas go, but it is still pretty cool. A plasma is essentially just an ionized gas (mainly oxygen or hydrogen in the plasmas I did) that can deposit atoms into the samples exposed to it.
To give an example of a common atomic defect in semiconducting crystals, oxygen vacancies form when there's an oxygen atomic site (i.e. a place in the crystal that's supposed to have an oxygen atom), but no oxygen atom is there. The idea with the oxygen plasma was to deposit oxygen atoms in the film to fill those vacancies in, although it actually had the opposite of the intended effect and created more of them. That was a bit confusing, but based on what I've been able to find online, the oxygen ions in the plasma can apparently bond with oxygen atoms at the surface of the material and rip them out of the film.
Thanks! It was a very stressful experience (writing the thesis, preparing for my defense, and the whole program in general), but I think I'm glad to have done it all even so. I learned a lot about semiconducting materials and crystals in general, which is what the whole degree was about basically. In terms of non-techincal things, I got a lot of practice with people skills. Most of the equipment in the lab I managed is pretty old, so (to put it politely) I also got a lot of troubleshooting experience. I enjoy working with hardware though on the whole, and I find it helps me understand the equipment a lot better when I have to fix it, so I can't complain too much.
