Dr Nathaniel Davis awarded Rutherford Discovery Fellowship

AUCAOS member Dr Nathaniel Davis has won a Rutherford Discovery Fellowship. The research is entitled “Pushing the limits on renewable energy technology through hybrid organic/inorganic nanomaterials”.

Follow the link below for further details:

https://www.royalsociety.org.nz/news/latest-10-fellows-announced-in-10th-year-of-rutherford-discovery-fellowship-awards/?fbclid=IwAR3MOgWQo4e4bVkLuP42vNsm4TZ1xrKdGxnA8nROPX7aHjzzVnDoZLBrVkg


ARENA announces funding of project to be led by AUCAOS member Dr David Jones aiming to increase solar cell efficiency.

The project is entitled “New Materials-Singlet Fission Enhanced Silicon Solar Cells” and aims to demonstrate effective use of high energy photons in order to improve solar cell efficiency by using multiple exciton generation (MEG).

This exciting project will include AUCAOS members Dr David Jones of Melbourne University, and Dr Paul Shaw and Professor Paul Burn of The University of Queensland.

For further information please follow the links below:

https://arena.gov.au/projects/new-materials-singlet-fission-enhanced-silicon-solar-cells/

https://arena.gov.au/news/research-boost-for-solar-panel-efficiency-and-cost-reduction/


Online Seminar Announcement: Wednesday 7 October 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 7 October

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/85305949649

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 Understanding the interplay between charge transport, luminescence efficiency and morphology in OLEDs using a combined computational & experimental approach

Mile Gao
The University of Queensland

Phosphorescent emissive materials in organic light-emitting diodes (OLEDs) manufactured using evaporation are usually blended with host materials at a concentration of 3–15 wt% to avoid concentration quenching of the luminescence. In this work, experimental measurements of hole mobility and photoluminescence are related to the atomic level morphology of films created using atomistic nonequilibrium molecular dynamics simulations mimicking the evaporation process with similar guest concentrations as that used in operational test devices. It was found that the photophysical and charge transport properties of the film have significantly different guest–guest distance dependence.

1:25 – 1:50pm The effect of gate conductance on hygroscopic insulator organic field effect transistors

Joshua Arthur
Queensland University of Technology

Organic thin film transistors (OTFTs), employing a variety of device architectures, materials, and transduction mechanisms, have shown great promise as effective chemical and biological sensors. One such class of OTFT is the hygroscopic insulator field effect transistor (HIFET). HIFETs utilise a hygroscopic polymer dielectric that behaves as a solid-state electrolyte, facilitating low voltage (<1 V) operation, in a simple, solution processable, solid-state form factor. Sensitivity to various analytes can be achieved by modifying the top gate electrode with appropriate porous membranes or recognition elements. However, a change to the electrical properties of the gate electrode can significantly degrade transistor characteristics. To better understand this behaviour, we have explored the effect of gate conductance on HIFET performance, using PEDOT:PSS films of varied thickness as a model gate electrode. As gate conductance increases, key figures of merit including ON/OFF ratio, threshold voltage and transconductance improve until approaching a plateau. We understand this effect in terms of a change in the magnitude of the effective gate voltage. These results imply widely applicable design rules, where good transistor functionality can be achieved with a range of gate conductance values that lie in the plateau region, allowing flexibility to incorporate poorly conducting materials that facilitate sensitivity.

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.


Associate Professor Prashant Sonar’s recent work highlighted in media including Brisbane Times and several journal covers

AUCAOS member Associate Professor Prashant Sonar’s research has recently been appeared in a number of publications including the Brisbane Times, as well as on a number of journal covers.

Please follow the links below for more information:

ACS Appl. Electron. Mater.:
https://pubs.acs.org/doi/abs/10.1021/acsaelm.0c00169
(Work highlighted on front cover)

Advanced Electronic Materials:
https://onlinelibrary.wiley.com/doi/abs/10.1002/aelm.202070025
(Work highlighted on front cover)

Advanced Materials:
https://onlinelibrary.wiley.com/doi/epdf/10.1002/adma.202001591
(Work highlighted on front cover)

Chem. Soc. Rev.:
https://pubs.rsc.org/en/content/articlehtml/2020/cs/c9cs00811j
(Work highlighted on back cover)

Brisbane Times Article:
https://www.brisbanetimes.com.au/national/queensland/researchers-see-the-light-by-turning-human-hair-into-oled-displays-20200602-p54yt6.html

Online Seminar Announcement: Wednesday 2 September 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 September

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/94754769654?pwd=ZDdkNXA0R0dkOXFhOTVzREJMT1ZTQT09

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 Nanoscale Capacitor-like Field Buildup Reveals Charge Protection in an Organic Heterojunction

Dr Kyra Schwarz
University of Melbourne

Emerging thin-film solar technologies often comprise nanoscale structural complexity that dramatically impacts the efficiency of light harvesting. Researchers have long considered how to suppress the loss of free carriers by recombination, an effect that is intimately connected to local morphology in the donor–acceptor heterojunctions of organic solar cells. Using femtosecond transient spectroscopies, we report the nanosecond grow-in of a large transient Stark effect, caused by nanoscale electric fields of ~487 kV/cm between photogenerated free carriers in the device active layer. We find that particular morphologies of the active layer lead to an energetic cascade for charge carriers, which in turn leads to the local build-up of electric charge that is resistant to bimolecular recombination and consistent with higher device efficiencies. These observations suggest that with particular nanoscale morphologies the bulk heterojunction can go beyond its established role in charge photogeneration and can act as a network of tiny capacitors, where adjacent free charges are held away from the interface and can be protected from bimolecular recombination.

1:25 – 1:50pm Design and Application of TADF Emitters for Blue and White OLEDs

Dr. Andrew Danos
Durham University

Thermally activated delayed fluorescence has allowed all-organic OLED emitters to reach the high efficiencies previously reserved by organometallic phosphors. Rapid reverse intersystem crossing (rISC) converts non-radiative triplet excitons into emissive singlets in devices, enabled by vibronic coupling of excited states with different multiplicity and orbital character. However this approach is not without drawbacks, and the complexity of the rISC process along with its strong sensitivity to host environment make it challenging to successfully design and implement blue and deep-blue TADF emitters.
Despite these challenges, recent progress in this area has been rapid. In this talk I will outline the general structural features required to design TADF materials, along with the experimental techniques used to screen and characterise their performance. Recent work applying external downconversion layers will also be presented, in which a high performance blue TADF OLED is modified to give white emission without loss of efficiency.

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.


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.


Online Seminar Announcement: Thursday 2 July 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: Thursday 2 July

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/96575282919

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 Hybrid organic/inorganic chromophores

Dr Nathaniel Davis
Victoria University of Wellington

Luminescent light harvesting chromophores have the potential to improve many optoelectronic technologies, such as photovoltaics, LEDS, lasers and luminescent solar concentrators. Our research into the creation of artificial light-harvesting antenna complexes aims to disrupt the current chromophore technology. The current state of the art chromophores can be split into two types: 1) Organics, which suffer heavily from instability and reabsorption; and 2) Inorganics, which solved many of the problems inherent with organic emitters in terms of stability and reabsorption but require complex surface treatments to improve their luminescent efficiency (LE). We aim to combine the beneficial properties of both these systems into a single hybrid chromophore. This will act to improve the LE of the hybrid particle and reduce reabsorption losses.
The science behind attaching chromophores to nanocrystals and studying the subsequent photophysics is in its infancy. We envision two options forward, that would promote the field, both based on the replacement of ligands on a nanocrystal that offer colloidal stability with ones that add additional optoelectronic properties. 1) Energy transfer from the ligand into the nanocrystal, which will have potential applications for increased solar absorption, efficient transport of excitations, and singlet fission. 2) Coupling a highly luminescent molecule to a nanocrystal, avoids the complex surface passivations (treatments) required by current state-the-art nontoxic emitters and offers the potential for upconversion of light.This talk will look at our recent success with caesium lead halide nanocrystals.

1:25 – 1:50pm Dicyanovinyl-based fluorescent sensors for dual mechanism amine sensing

Dr. Guanran Zhang
University of Queensland

Food wastage due to spoiling is a global economic issue and contributes to over-farming and overfishing with real environmental consequences. Smart food packaging is a promising solution to this problem, the idea of which is to utilize responsive sensors that allow direct monitoring of the gasses released from food as it spoils and provides a visual indicator to the consumer. Here we report two dicyanovinyl-fluorene-benzothiadiazole-based fluorescent compounds, K12 and K12b, both of which showed rapid response to biogenic amines via two independent mechanisms. When primary alkyl amines were present in solution, they underwent Michael addition with the dicyanovinyl group of the sensing material, resulting in rapid color change. The reaction products of K12 and K12b with primary amines also showed a decrease and increase in the fluorescence quantum yield, respectively, enabling a unique dual-sensor array with turn-off/turn-on response. In addition, fluorescence quenching via photoinduced hole transfer was observed in the solid-state sensor films with a wide range of primary, secondary and tertiary amines, enabling rapid and sensitive detection of amine vapors. Finally, as a proof-of-concept integrated packaging sensor, soft membranes incorporating K12 and K12b were prepared and showed rapid response to primary amine vapor.

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.


Online Seminar Announcement: Thursday 4 June 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: Thursday 4 June

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/99887544733?pwd=TVk1ZFl3WGtSWHJmMTM3dG9BVk1jQT09

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 An introduction into synthetic molecular motors

Jos Kistemaker
The University of Queensland

Scientific advances made in the last three decades, inspired by Nature’s example, has led to a diverse collection of synthetic molecular machinery. A prominent example of this machinery is the molecular motor developed by Feringa and co-workers which is based on a light driven overcrowded alkene. The study of several generations of molecular motors and their properties have had primarily academic merit, however, later developments have shown that these nanomachines can be used to do actual work and might prove to be the driving force in the transition to actual applications.
This talk will provide an introduction into the field of synthetic molecular motors with an emphasis on light driven rotary motors. The role of autonomy and chirality in different designs will be highlighted and several examples will be used to showcase the expression and translation of these features to other groups, molecules and larger scales.

1:25 – 1:50pm Electronic coupling: A significant contributor to electron transfer between similarly structured surface-bound porphyrins and Co2+/3+ complex electrolytes

Mr Inseong Cho
University of Wollongong

Electronic coupling is often assumed to play a minor role in interfacial electron transfer (ET) between similarly structured electron donors and acceptors. To check this assumption, we investigated the ET kinetics between four surface-bound free-base and Zn porphyrins and five Co2+/3+ complexes redox mediators with different ligands using transient absorption spectroscopy (TAS). The ET rates measured in this work are the fastest reported in the literature for surface-bound molecules and donors dissolved in electrolytes. By using a novel sub-ns TA setup, the importance of enhanced TAS time-resolution is demonstrated. Fitting the measured ET rate versus –ΔG resulted in poor fits with unrealistic trends in reorganisation energy values. This is explained by up to 60% variation of the electronic coupling (HDA) depending on the size of the alkyl-substituent of the Co2+/3+ complexes redox mediator. The HDA values obtained by assuming a constant reorganisation energy are shown to be dependent on tunnelling distances, characterised by tunnelling attenuation factor βel = 0.16 to 2.0 Å-1. This work suggests that changes in electronic coupling even by small structural modification previously considered negligible can be as significant as the effect of driving force.

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.