Online Seminar Announcement: Wednesday 1 December 2021

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

Meeting URL: https://jcu.zoom.us/j/81453304396

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

Synthesis of 2D nanomaterial from waste and its application in opto-electronic and sensing

Amandeep Singh Pannu

Queensland University of Technology

The study investigates an end-to-end solution for developing carbon based 2D semiconductor nanomaterial or quantum dots from carbon rich bio-waste and demonstrates its application into thin film devices and solution based optical sensing. The presentation is divided into two parts. The first part will share the outcome of study, which explores the synthesis method to produce such high performing quantum dot material and tune its opto-electronic properties via surface engineering based on its application either in sensing or active/charge transporting layer in light emitting diodes and solar cell devices. The second part of the presentation will share the insights on how to apply this synthesized material successfully into hybrid devices.

 


Presentation
1:25 – 1:50pm

Harnessing triplet excitons in organic solid-state lasers

Atul Shukla

The University of Queensland

Organic light-emitting device technology has been shown promising for a paradigm shift from organic light-emitting diodes (OLEDs) to organic laser diodes (OLDs).[1] While significant progress has been made for organic semiconductors emitting in the blue–green region of the visible spectrum, organic laser dyes with low-energy emission (>600 nm) still suffer from high amplified spontaneous emission (ASE) thresholds and low external quantum efficiencies (EQEs) in devices under high current densities.[2, 3] In this presentation, low ASE thresholds and efficient electroluminescence (EL) from a solution-processable organic laser dye dithiophenyl diketopyrrolopyrrole (DT-DPP) will be shown. A low ASE threshold of 4 μJ cm−2 with λASE ≈ 620 nm will be presented by making constructive use of triplet excitons via doping DT-DPP in a green-emitting host matrix that exhibits thermally activated delayed fluorescence (TADF). A high EQE of 7.9% of fabricated OLEDs due to the efficient utilization of triplet excitons is demonstrated. Finally, the critical role of reverse intersystem crossing rate in achieving lasing under electrical pumping from such TADF-assisted fluorescent systems will be discussed using transient EL studies.[4]

References:
[1] A. S. D. Sandanayaka, et al., Appl. Phys. Express, 12, 061010 (2019).
[2] M. Mamada, et al., Adv. Funct. Mater., 28, 1802130 (2018).
[3] A. Shukla, et al., Adv. Opt. Mater., 8, 1901350 (2020).
[4] A. Shukla, et al., Adv. Funct. Mater., 31, 2009817 (2021).


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 typically held on the first Wednesday of each month.

At this time we are specifically encouraging HDR students to present their work to broad audience. If you are interested in speaking then please submit an abstract to bronson.philippa@jcu.edu.au.