Materials from Past Webinars in 2026

Synopsis: 

Interfaces in semiconductor devices contain high defect densities that affect carrier dynamics and long-term stability. In halide perovskites, probing these effects is particularly challenging due to their ionic lattices and complex interactions with contact materials. Although interface passivation is widely adopted, establishing direct correlations between interfacial structure and device performance remains a major challenge.

In this talk, I first present our work of structure-property relationship in Dion–Jacobson (DJ) perovskites, a promising class of stable photovoltaic absorbers. Using a non-destructive peel-off technique combined with spectroscopy and microscopy, we directly probe buried interfaces and reveal that multiscale inhomogeneities, more prevalent at buried layers than surfaces, act as performance-limiting defects. A sulfate-based inner-sphere complexation strategy is developed to passivate crystal terminations and promotes uniform crystal growth, yielding record efficiencies in DJ perovskite photovoltaics. I then share our recent findings that carrier-selective interface degradation is a key barrier to commercializing perovskite photovoltaics. In situ electrical tracking identifies fill-factor loss as a dominant degradation mode, linked to thermally induced disorder in commonly used monomeric molecular contacts. We address this by introducing in-situ Schiff-base polymerization to stabilize delicate interfaces, resulting in much improved thermal and operational device stability.

Students and teachers may visit this SLS module for more content related to this webinar: 

https://vle.learning.moe.edu.sg/admin/moe-library/module/view/bcd2a131-d170-4fe1-b864-5400b4a042f2

Synopsis: 

The environment plays a key role in disease transmission. For example, dengue and Zika are spread through mosquito vectors, and respiratory pathogens such as coronaviruses can spread through close contact and airborne particles. Intelligence on risk factors, as well as innovative measures to safeguard a healthy environment are essential for preventing transmission, and are even more critical against a backdrop of climate change and globalisation. We will explore how multi-source surveillance data (e.g. cases, mosquito populations, and the presence of viruses in wastewater) can be integrated for risk assessment, allowing control measures guided by data. An example of an innovative control approach is Project Wolbachia – Singapore, which involves the release of male mosquitoes carrying the Wolbachia bacteria to suppress urban dengue mosquito populations. We will explore how developing and scaling this approach has required expertise from multiple disciplines, including entomology, data analytics, engineering, and social science.

Synopsis: 

Seagrass meadows are powerful yet often overlooked natural climate solutions. As one of the most efficient blue carbon ecosystems, they capture and store significant amounts of carbon in their biomass and sediments, contributing directly to climate mitigation while supporting rich coastal biodiversity. However, climate-driven stressors, including warming waters, marine heatwaves, and extreme weather, combined with local human pressures, threaten the stability of these carbon stores and the resilience of the ecosystems that house them. This talk explores how environmental stress affects seagrass productivity, carbon sequestration, habitat structure, and the marine food webs they sustain. Using examples from tropical regions, we examine the feedback loops between seagrass loss and greenhouse gas emissions, the consequences of habitat degradation on biodiversity and fisheries, and the potential for seagrass protection and restoration to enhance climate resilience. This session integrates ecological principles with real-world blue carbon science to highlight why safeguarding seagrass meadows is essential for a sustainable climate future. 

Check out more resources by Dr Siti Yaakub here:

Straits Times article: https://www.straitstimes.com/science-talk-there-is-climate-value-in-south-east-asias-protected-areas-but-were-failing-to-use-it

Her World Article: https://www.herworld.com/independence/career/dr-siti-maryam-yaakub-protecting-singapores-shores-through-our-seagrass-meadows

Podcast: https://youtu.be/21LP8cJzZLg?si=h_4r0n6aCY_lnHr3

Synopsis: 

Charles Darwin and Alfred Russel Wallace are credited as the co-founders or co-discoverers of evolution by natural selection - one of the most revolutionary scientific developments in history. Their stories have been told many thousands of times for over 150 years. Unfortunately, with the passage of time and the retelling done mostly by writers who are not historians of science, the story has become very different from the historical reality and is now full of myths and mistakes. Many of these new stories are highly cherished now and few outside of professional history of science are aware of how false these stories are. In this talk an overview of the actual origins of modern evolutionary theory will be given and some of the biggest myths exposed.