Showing posts with label solar cells. Show all posts
Showing posts with label solar cells. Show all posts

Saturday, January 14, 2012

excitement vs. math

remember when I was really excited about my solar cell class??

yeah, that was after day 1. My feelings have rapidly u-turned, as illustrated by this graph I drew on my phone:


I'm currently on hour 7ish of working on the homework assignment, and have yet to answer even a single part of one of the two problems assigned. I apparently don't understand anything about lasers, flux, blackbody radiation, solar cells, etc and both my textbook and the internet are not helping. at all. Also, I'm pretty sure that I'm the only person in the class who used excel to do the last homework.....I never had to learn any sort of higher-level math program (MatLab, Mathematica, etc) in college. Learning one of those programs is on my list of things to do, soon.

And thanks to the holiday on Monday, I don't even think I'll be able to meet with my prof to discuss the homework. also, I lost my husky card yesterday which made Friday not a fantastic day at all, excluding the time spent rock climbing. That was fun, but since I lost my husky card, I can't go climbing again tomorrow, as was my plan.

At least today is Saturday.

Tuesday, January 3, 2012

Q2

Today marks the first day of my second quarter in grad school. wow.

I met all the students I'll be TA-ing for over the course of the quarter: 38 boys and 8 girls. I guess that is engineering for you. Interestingly, all the TAs are women. Hopefully I didn't scare/annoy them too much with my page-long email and extra work I just assigned....it's going to be a fun quarter.

I think, however, that the most interesting part of my quarter is going to be this intro/get-everyone-up-to-speed photovoltaics course I'm taking from the Chem E department. I realized as my prof was giving his intro lecture that I had already read and cited a paper he wrote in my quarter report and some of my fellowship applications. Pretty sure I wasn't aware that the author of that paper was at the UW. Mainly, I'm just more excited than ever to work in the renewable/alternative energy sector. Solar is a very viable technology for energy independence, good stewardship of our natural resources, etc, etc, etc. While sitting through this class, I was almost overwhelmed (that sounds more dramatic than reality) with excitement that I possibly get to spend my career researching solar energy conversion. Kind of nerdy, I know, but I'm slowly realizing that I'd be very okay with staying in the solar sector. There are just so many interesting aspects - from the materials, to the processing, the device design; even energy policy is something I've been looking into .

favorite picture from the intro lecture:


notice the color over seattle? yeah. I just laughed when this popped up.
probably going to have to move to do this solar energy career. 

Monday, December 5, 2011

diodes

first, thank you to all my EE inclined friends who have been teaching me the basics of everything I probably should have learned at some point before starting a solar cell project....I'm slowly learning and absorbing all this new material.


this thursday, if someone questions my understanding of diodes when I try to explain how solar cells (p-n junctions) work, I'm just going to quote my favorite EE:


so it's like a door really
if you push it the wrong way, it won't open
and if you push it the right way, but not hard enough, it won't open
otherwise it opens and the electrons can walk right through
if you put a ton of current going the wrong way, it'll burn up



basically it's like throwing flaming bowling balls at a door going the wrong way
eventually they get through
and burn up the door in the process
then it just works as a wire
but smells bad
kind of charred





best moment during my night of panicked studying. 

Tuesday, October 18, 2011

....seminars....

One part of grad school I did not expect was the number seminars I have to attend. I'm just shy of three weeks in and I've already listened to 6 seminars and have one more to go this week. (this week is unusual, mainly because my sol-gel class has morphed into guest seminars for both classes this week, so I going to 4 seminars). and last week, I went to a seminar outside of school, as I finally made it one of Seattle's Science Cafes.

This summer, I could go to just one or roughly four different seminars a week, and they usually had cookies aft wards :) I enjoy going to seminars, and as uninteresting as the titles may sound, I've found that I usually find something intriguing in each one. That doesn't always mean that I actually understand much of what is being discussed, but I try to pay close attention...promise.

Anyways, one of our seminars was actually pretty pertinent to what I am planning on researching - solar cells! This professor from the University of Illinois (who is taking a sabbatical in Oregon??) researches something called CIGS - they are a specific type of solar material that is made of Copper, Indium, Gallium, and Selenide (I think) and are becoming more promising with increased efficiencies and lower manufacturing costs. However, I am not a super big fan of the device because it still uses both CdS for an absorber layer, which is toxic (though he did say that should a house burn these panels on the roof, the vapor was not concentrated enough to be toxic) and the cells rely on indium, an element which, to the best of my knowledge, is only available in China. And I heard that recently China's been increasing prices of certain metals, and though I'm not sure if indium is one of them, I wouldn't be surprised. I think every current solar cell uses it in some form. The only major point I disagreed with his assertion that we should only focus on efficiency of the cells and that going for a cheaper, but less efficient material was a good problem for 'academia' but not really commercially feasible. Maybe it's just because that's what my thesis focuses on, and I'm a bit biased, but I think that using a cheaper, less toxic, easier to manufacture material can be a good tradeoff with a decreased efficiency. But we'll see. Ask me again in 5 years how I feel about that :)

Today's substitute sol-gel seminar was barely related to sol-gel processing (actually, I can't really figure a connection) but really interesting. It focused on a new idea for storage of energy generated from solar cells - splitting water. Since solar cells only work during the daylight hours, what happens when you need electricity at night? You can produce more electricity during the day than you use, but if you can't store it, then you lose it. One of my favorite companies, A123 Systems in MI, has developed a more efficient battery that can possibly 'stabilize the grid', basically store excess power and meter it out when needed. But this prof was discussing how if we split water into it's respective H2 and O2 components, then later on we could recombine them and get energy out when they form H2O again. Yes, you'll lose some energy to splitting the original water, but not as much as if you lost all the excess energy by not trying to store it. They are even working on developing solar cells of sorts that can sit in a clear bucket of water and just by absorbing light can power reactions that split water. To cool! Here is a sweet video he showed us, the bubbles on the front are O2 and the ones on the back are H2. There are no wires, no membranes, no nothing besides this complicated, layered metal.


Isn't it pretty?!

The other seminars - not so interesting. I may have found a new technique that will be helpful in determining charge carrier mobility (basically, how far can an electron or electron hole move in my material) but it also looks like a complicated set up :/

One seminar had lots of cool pictures because they were causing supramolecular structures to self-assemble in monolayers - randomly dispersed pieces of a puzzle come together in an ordered/patterned fashion by themselves. And they make really cool SEM pictures:



(the green overlays are the molecule outlines)

All I could think about during the lecture was how they would look really incredible blown up really large or shrunk to a small pattern and used in a dress....like these atomic bomb images were used:




(Christopher Kane's 2010 Resort Collection)


I just calculated that I'm required to go at least 90 seminars so that I can finish my degree. Oh boy.