Online Seminar Announcement: Wednesday 2 December 2020

Due to the cancellation of many scientific conferences, the AUCAOS committee is pleased to announce an online seminar series. We intend to run seminars on the first Wednesday of every month until normal conferences can resume.

Date: Wednesday 2 December 2020

Time:
1pm in QLD
2pm in NSW, ACT, Vic and Tas
11am in WA
12:30pm in NT
1:30pm in SA
4pm in New Zealand

Click this link to join the meeting: https://jcu.zoom.us/j/84452910435

Seminar schedule
Each talk is 20 minutes duration followed by approximately 5 minutes for questions and discussion.

Time (QLD time, adjust as needed): Presentation:
1:00 – 1:25pm Non-Toxic Hybrid Inorganic-Organic Chromophores for the Advancement of Luminescent Solar Concentrators

Calum Gordon
Victoria University of Wellington

Luminescent solar concentrators (LSCs) consist of a waveguide medium containing light harvesting chromophores of an inorganic or organic nature. These chromophores absorb incoming light, and radiatively re-emit light, which is propagated to the edges of the LSC by the waveguide. The concentrated light at the edges is then collected by coupled solar cells.
The advantages of LSCs coupled to solar cells relative to stand alone solar cells are that LSCs are cheaper, and can capture indirect sunlight.
A pressing issue with modern LSCs are re-absorption events by the chromophore, which dampens their efficiency. This is due to overlap between the absorbance and emission spectra of the chromophore.
By coupling inorganic and organic components together, Förster resonance energy transfer (FRET) may be achieved between the two components, creating a donor-acceptor system. The donors absorbance spectrum is sufficiently separated from the acceptors emission spectrum, mitigating re-absorption events.

1:25 – 1:50pm Magnetic field effect on UC-TTA

Elham Gholizadeh
The University of New South Wales

Solar light contains many wavelengths, but solar cells cannot absorb all those wavelengths. In fact, those photons which do not have enough energy to be absorb by the band gap will be wasted. One of the strategies that have been used until now in terms of using low energy photons is Triplet-Triplet Annhilation upconversion (UC-TTA). In this process two low energy photons will convert to a higher energy photon.
In terms of improving solar cells efficiency, it is important to make an upconversion system which convert photons below the bandgap to the photons that absorb by the solar cell. Also, since most of the upconversion system does not work in oxygen environment, finding a solution for this problem looks essential.
In my PhD, I could do UC-TTA from below the silicon bandgap in oxygen mediated environment. In this system, opposite other UC-TTA systems, oxygen improves the upconversion efficiency. So, in terms of understanding the mechanism of UC-TTA in our system in the presence of oxygen, magnetic field effect on TTA process was used. We also considered magnetic field effect on two well known UC-TTA system to be able to modify Merrifield equation and the data was fitted by this equation.

1:50 – 2:00pm Open discussion

 

During the seminar:

  • Please keep your microphone muted unless you are speaking. This is to reduce the background noise and avoid disrupting the presenter.
  • You will be automatically muted when you join the virtual meeting room. To speak, you will need to unmute yourself by using the audio controls in the lower left of the Zoom window.
  • If you have not used Zoom before, then it is recommended that you join 5 minutes before the starting time to ensure that you have your software set up correctly.

Please be aware that the talks will be recorded and posted on the AUCAOS website.

Previous seminars

Previous seminars can be viewed here: https://seminars.aucaos.org.au/

Call for abstracts

Seminars are held on the first Wednesday of each month.

In the spirit of building a community in these challenging times, you are encouraged to give a talk. Do you have a talk that you would have given at a conference that was cancelled? Please consider adapting that talk for this format.

Submit abstract by email to bronson[dot]philippa[at]jcu[dot]edu[dot]au.