tag:blogger.com,1999:blog-7507812202575933663.post8720543414980024717..comments2023-05-17T01:48:52.795-06:00Comments on infiniflux!: In which I try to recap a whole summer of infiniflux? part 1.Joel Kellyhttp://www.blogger.com/profile/04844525141112359095noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-7507812202575933663.post-55013539355910402342009-09-10T21:42:29.893-06:002009-09-10T21:42:29.893-06:00Thanks Jes! That definitely helps. And I am defini...Thanks Jes! That definitely helps. And I am definitely going to check this Igor thing out.Joel Kellyhttps://www.blogger.com/profile/04844525141112359095noreply@blogger.comtag:blogger.com,1999:blog-7507812202575933663.post-33871216797503621552009-09-08T15:27:17.829-06:002009-09-08T15:27:17.829-06:00i like to avoid CV too--IMO, energy levels are bet...i like to avoid CV too--IMO, energy levels are better determined by UPS. ;)<br /><br />Upon photoexcitation, an electron is excited from the donor's HOMO to the donor's LUMO, leaving a hole in the donor's HOMO. This bound electron-hole pair is called an exciton, and if you're lucky and it's able to reach the donor-acceptor interface, the electron can be transferred from the donor's LUMO to the acceptor's LUMO. (You need the acceptor's LUMO to be at least ~0.3-0.4 eV lower than the donor's LUMO for that to happen, and a similar offset for the HOMO levels so that holes can be transferred from acceptor HOMO to donor HOMO--because the acceptor is probably absorbing light too.) The simplified picture that a lot of people present is that the energy difference between donor HOMO and acceptor LUMO is the Voc--and the larger the Voc, the higher the power conversion efficiency that's possible, so you definitely want a large dHOMO-aLUMO gap. <br />(Of course, the Voc depends on a lot of other factors that aren't easily determined, so it actually ends up a little smaller than the aforementioned dHOMO-aLUMO gap...but that's going into way more detail than most people care about.)Ψ*Ψhttps://www.blogger.com/profile/15089754859676425655noreply@blogger.comtag:blogger.com,1999:blog-7507812202575933663.post-20423291645945022332009-09-08T12:50:19.211-06:002009-09-08T12:50:19.211-06:00Hi Jes! Thanks for commenting!
I re-read your pos...Hi Jes! Thanks for commenting!<br /><br />I re-read your post, and it makes sense on how to derive the Voc and Jsc from those C-V curves. I just don't have an intuitive understanding of what those values actually mean as a chemist who has successfully avoided electrochemistry like the plague up until this point. Why is a large donor HOMO and acceptor LUMO gap desireable for a large Voc?<br /><br />Ahh. C-V curves make brain hurt. Ouch.Joel Kellyhttps://www.blogger.com/profile/04844525141112359095noreply@blogger.comtag:blogger.com,1999:blog-7507812202575933663.post-5734614578394695252009-09-08T00:29:53.378-06:002009-09-08T00:29:53.378-06:00me? expert? you're very funny :)
i tried to ...me? expert? you're very funny :)<br />i tried to explain Voc and related concepts <a href="http://www.coronene.com/blog/?p=927" rel="nofollow">here</a>...is further clarification needed? i've been working on these things for so long that the basics are almost second nature, and it's easy to forget how little exposure to these concepts most people get...Ψ*Ψhttps://www.blogger.com/profile/15089754859676425655noreply@blogger.com