Online Seminar Announcement: Wednesday 5 August 2020

The AUCAOS online seminar series will now be held on the first Wednesday of every month. Please see details of the next seminar below.

Date: Wednesday 5 August 2020

Time:
1pm (QLD, NSW, ACT, Vic, Tas)
12:30pm (SA, NT)
11am (WA)
3pm (New Zealand)

Click this link to join the meeting: https://jcu.zoom.us/j/99265923575?pwd=Q3J0SEdzSjNxdnhMaThYalhoWnltQT09
Password: 225154

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 Characterising the Interface and Dipole in Organic-based Photovoltaics

Dr. Yanting Yin
Flinders University

A combination of electron spectroscopy and ion scattering spectroscopy has been carried out to directly characterize the chemical and electrical properties at the interface formed with high workfunction (WF) hole transport layer-MoO3 and conjugate polymer. Characterization of chemical features and concentration distribution on a P3HT:PC61BM bulk-heterojuction (BHJ) with MoO3 arises an observation of energy shift of BHJ and diffusion of MoO3. The dipole formation at such interface can be indicated. Gradual changes upon electronic structure such as WF and valence electron states were observed from the analysis. A decomposition algorithm introduced in the work yields an insight into the dipole strength thus the complete energy level positioning at the interface can be restored. The mechanism of charge transport over the MoO3/BHJ interface was thus discussed with the determination of dipole strength maximizing at 2.1eV. A similar characterization upon interface was studied upon the growth of thermal-evaporated LiF on polymer BHJ. Further investigation has been made of the interface with a simulation of common contamination such as air exposure, and commercialized fabrication process such as thermal annealing consequence during fabrication. The results show that, the electronic properties of the original interface can be altered once the structure was subjected to contamination and thermal treatment. The analysis offers an insight of device performance of solar cells correlated to interface dipole features.

1:25 – 1:50pm Red Emission from Nature Inspired Bay-Annulated Indigo Derivatives

Ms Nicholle Wallwork 1,2
University of Queensland

Atul Shukla,1,3 Xin Li,1,2 Jan Sobus,1,3 Van T. N. Mai,1,2 Sarah K. M. McGregor,1,2 Kay Chen,2 Romain J. Lepage,2 Elizabeth H. Krenske,2 Evan G. Moore,2 M. Mamada,4 C. Adachi,4,* Ebinazar B. Namdas,1,3* Shih-Chun Lo1,2*1. Centre for Organic Photonics & Electronics, The University of Queensland, Brisbane, Queensland, 4072, Australia
2. School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, 4072, Queensland, Australia
3. School of Mathematics and Physics, The University of Queensland, Queensland, Brisbane, Queensland, 4072, Australia
4. Centre for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan

Organic semiconductor materials offer high mechanical flexibility and high wavelength-tunability, which have great potential as a complementary technology to current inorganic lasers, particularly for spectroscopy, sensing, optical data communication, display, and security tag applications.1 Recent research efforts on organic semiconductor lasers have demonstrated notable organic semiconductor materials possessing both high optical gain and low amplified spontaneous emission (ASE) thresholds in blue and green colours.2 However, the same progress has not been made on red laser dyes mainly due to their low photoluminescence quantum yields (PLQYs) recognised as the “energy bandgap law” for low-energy emission.
To overcome this, in this presentation our development of a new family of solution-processable organic semiconductor laser dyes with deep-red emission, high thermal stability and high PLQYs (≈100%) will be shown. Our strategies in achieving low film ASE thresholds (9.6 μJ/cm2 at 650 nm), low laser thresholds (6 μJ/cm2) and high stability under optical pumping (retained 90% of the initial output even after ≈9,600 pump pulses of continuous pumping at 20 Hz) will be further discussed.3 Finally, our preliminary work on TADF-Assistant Fluorescent OLEDs (TAF-OLEDs)4 based on the new red laser dyes will be demonstrated to show high promise as a new family of organic semiconductor materials.

References: 1. A. J. C. Kuehne, M. C. Gather., Chem. Rev. 2016, 116, 12823. 2. T. N. V. Mai, A. Shukla, M. Mamada, S. Maedera, P. E. Shaw, J. Sobus, I. Allison, C. Adachi, E. B. Namdas, S.-C. Lo, ACS Photonics 2018, 5, 4447; Y. Oyama, M. Mamada, A. Shukla, E. G. Moore, S.-C. Lo, E. B. Namdas, C. Adachi, ACS Mater. Lett. 2020, 21, 161. 3. A. Shukla, N. R. Wallwork, X. Li, J. Sobas, V. T. N. Mai, S. K. M. McGregor, K. Chen, R. J. Lepage, E. H. Krenske, E. G. Moore, E. B. Namdas, S.-C. Lo, Adv. Opt. Mater. 2020, 8, 1901350. 4. H. Nakanotani, T. Higuchi, T. Furukawa, K. Masui, K. Morimoto, M. Numata, H. Tanaka, Y. Sagara, T. Yasuda, C. Adachi, Nature Commun. 2014, 5, 4016.
Acknowledgement: We thank Australian Research Council (DP160100700 and DP180103047), and Department of Industry, Innovation and Science (AISRF53765), and Japan Society for the Promotion of Science (JSPS Core-to-Core 18050011-000441) for financial support.

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.