Six exciting new ACAP Collaborative Research Projects

Challenge 

Developing non-Si-based tandem solar cells offers several benefits, including lower production costs, design flexibility, reduced material usage, and the potential for higher efficiency. Monolithic Perovskite/CZTSSe tandems are a promising candidate: they combine the efficiency potential of perovskites, the relative sustainability of CZTSSe, and the cost-effectiveness of monolithic thin-film fabrication (vs mechanically stacking two separate finished cells). However, the fabrication of a monolithic perovskite/CZTSSe device remains a challenge. 

Solution 

In this project, CSIRO will apply its patented chemical vapor deposition (CVD) technology to produce high-quality, uniform, and scalable perovskite films with tailored bandgaps, which will be integrated onto UNSW’s low-bandgap CZTSSe cells to demonstrate a functional perovskite/CZTSSe tandem device. 

Collaboration 

The project combines CSIRO’s scalable perovskite fabrication technology with UNSW’s high-efficiency low-bandgap CZTSSe bottom cells. The research will address the challenges related to interface and interconnection. Understandings will be shared through collaborative publications, reports, and conference presentations.  

 Impact 

This project will pioneer the development of a novel, low-cost all-thin-film perovskite/CZTSSe tandem solar cell, offering significant potential for advancing non-Si tandem photovoltaic technologies. 

Lead CI Yong Li (CSIRO) said, “This work exemplifies the unique opportunities presented by combining the expertise and technological capabilities of ACAP’s nodes.” 

Challenge 

 While TOPCon solar cells offer high efficiency, their rapid adoption is limited by concerns over their long-term stability, particularly in relation to UV-induced degradation, corrosion, and thermal instability. These are key mechanisms that can reduce module lifetime and undermine the economics of ultra-low-cost solar. 

Solution 

This project will uncover the root causes of these degradation mechanisms and develop strategies to mitigate them, guiding the design of more durable TOPCon cells that sustain high performance over time. 

Collaboration 

 UNSW, ANU, and CSIRO are combining expertise: UNSW will focus on cell and mini-module testing; ANU will lead modelling of long-term behaviour under various environmental conditions; and CSIRO will provide high-precision field testing and module performance analysis. 

Impact 

By improving the durability and reliability of TOPCon technology, the project will provide critical insights for the industry and support the deployment of ultra-low-cost solar at scale. 

Project Lead Bram Hoex said, “We expect significant industry interest and impact in this work, as we have seen in our other work to date on TOPCon and HJT reliability.” 

Challenge 

The PV industry is heading for terawatt-scale deployment, but today’s low-temperature interconnections consume large amounts of scarce bismuth (Bi), creating a major bottleneck for scaling next-generation solar cells like HJT, TOPCon, and perovskite tandems.  

Solution 

This project tackles that challenge with a patented method to cut Bi use by over 90% by forming tin-bismuth alloy only where needed, rather than coating entire interconnection ribbons. The project will build on a recently submitted provisional patent and a short ACAP fellowship project.    

Collaboration 

UNSW will lead the Bi-lean technology development, while ANU will fabricate high-efficiency cells to test integration with advanced metallisation schemes. The two nodes will collaborate closely, exchanging staff and students to refine processes and validate performance across different designs. 

Impact 

Mainstream screen-printing technology will be used to enable straightforward technology transfer to industry and accelerate the commercialisation of developed technologies.  

UNSW has established industry partners, including leading paste and module manufacturers (as part of ARENA/TRAC003 project), and fast and smooth technology transfer to industry can be expected.   

Project Lead Sisi Wang said, “The technology removes a key material sustainability risk, is compatible with existing industrial processes, and offers rapid pathways to commercialisation, strengthening both sustainability and supply chain resilience.” 

Challenge 

 By 2050, up to 78 million tonnes of solar panel waste could be generated globally, yet many decommissioned panels are still in working condition. Their safe reuse, however, is restricted by current standards and there’s no scalable, reliable testing that can sort them for re-use or recycling. 

Solution 

This project is developing software to automatically determine the Residual Useful Life (RUL) of panels. By providing a reliable estimate of the panel’s remaining useful life, it enables rapid sorting for re-use or recycling and diverting millions of modules from landfill.  

CSIRO will integrate the software into its PV Rapid Triage Test Rig, replacing the current reliance on expert judgement. UNSW is leading software development, while ANU is establishing the scientific framework linking test data to RUL and conducting material fingerprinting to connect panel design with degradation patterns. 

Collaboration 

CSIRO will integrate the software into its PV Rapid Triage Test Rig, replacing the current reliance on expert judgement. UNSW is leading software development, while ANU is establishing the scientific framework linking test data to RUL and conducting material fingerprinting to connect panel design with degradation patterns. 

Industry Impact 

With backing from Second Life Solar and PV Industries, the project has strong commercial relevance. Defining and embedding RUL in testing could unlock regulatory change, new business models, and greater industry confidence in reusing solar panels. 

Project Lead Chris Fell (CSIRO) said, “By creating the technology to rapidly sort large volumes of PV modules for re-use or recycling, we’ll open up business models that divert millions of PV modules away from the waste stream.” 

Challenge 

Ultra-low-cost solar could cut electricity prices by a factor of 2–5, but its system-wide impacts and industrial opportunities are not yet well understood by the public, investors or policy makers. 

Solution 

This project will model how ultra-low-cost solar affects electricity costs in a decarbonised system, and it will map opportunities from ultra-low cost solar in new industries, providing vital insights for policymakers in Australia and worldwide. 

The project develops advanced models to quantify cost reductions in high-renewable energy systems and maps new opportunities in industries such as: 

• Producing synthetic aviation and shipping fuels from captured CO₂ 

• Large-scale carbon capture and underground storage in central Australia 

• Replacing gas in industrial furnaces and chemical production 

• Harnessing surpluses of very cheap rooftop solar. 

Collaboration 

Led by ANU and UNSW, the project combines expertise in energy modelling and techno-economic analysis to identify and evaluate opportunities and pathways and for ultra-low-cost solar across industries. 

Industry Impact 

Findings will guide companies, governments and analysts in planning for a future where Australia’s access to the world’s cheapest energy creates new markets and investment pathways. Results will be openly shared to maximise impact. 

Project lead Kylie Catchpole (ANU) said, “This project will offer crucial insight for industries and government on the opportunities for deep decarbonisation offered by ultra-low-cost solar.” 

Challenge

Silicon tandems could deliver >30% efficiency, but suitable top-cell materials are scarce. Only seven semiconductors have achieved >20% efficiency, with lead-halide perovskite the only non-adamantine option — yet it faces serious stability and environmental concerns. This creates a major barrier to the commercial rollout of silicon tandems.

Solution

A recent UNSW patent has doubled the pool of promising adamantine candidates. This project will begin experimental studies on selected sulphide compounds predicted to have strong potential, focusing first on synthesising samples and measuring their optical properties to confirm theoretical models.

Collaboration

• UNSW – material synthesis and characterisation

• University of Sydney – tandem device expertise

• CSIRO (Newcastle) – advanced analysis and testing

External specialist groups in sulphide synthesis may also be engaged.

Impact

The project aims to uncover abundant, stable, non-toxic materials for tandem integration, reducing reliance on perovskites. Outcomes will guide the development of >30% efficiency silicon tandems, supporting Australia’s leadership in ultra-low-cost solar. A Phase I report will be delivered by the end of 2025 with pathways for future research.

Project Lead Professor Martin Green said: “By expanding the pool of viable materials beyond perovskites, this work could transform the landscape for silicon tandems and bring 30% efficiency solar modules within commercial reach.”