UNSW and UtmoLight achieve certified 23.5% efficiency for perovskite submodule

Researchers at UNSW Sydney, led by Scientia Professor Xiaojing Hao, have achieved a certified stabilised power conversion efficiency of 23.5% for a perovskite solar submodule. The record, set in partnership with Chinese manufacturer UtmoLight, was reached by removing the conventional nickel oxide layer from the cell's architecture.

Nickel oxide is commonly used in perovskite solar cells to prevent electrical short circuits. The UNSW team stated this layer can react adversely with the perovskite material, adding instability and an extra manufacturing step. Their innovation used a different fabrication approach, enabling a hole-selective contact to form directly during processing rather than through layer-by-layer deposition.

The perovskite submodule has an aperture area of 676 cm², measuring 30 cm by 30 cm. This result beats the previous benchmark by 0.6 percentage points. Small laboratory cells are typically around 1 cm². The achievement narrows the efficiency gap between lab-scale devices and industrially relevant areas.

Implications for scalable manufacturing and industry relevance

The result demonstrates perovskite technology can maintain high efficiency at larger scales through scalable fabrication approaches. Materials that perform well in small laboratory devices do not necessarily behave the same way in larger areas. The work highlights the potential for widespread use in photovoltaic modules.

Xiaojing Hao said the aim goes beyond setting another efficiency record. "It is about developing materials and device concepts that continue to perform when they are translated from laboratory cells to industrially relevant areas," she explained. Achieving high efficiency at this scale requires much more than simply transferring a laboratory process to a larger substrate. The collaboration allows early testing of scalability, avoiding years of lab-only innovation that may not translate to industrial scale.

Pathway to full-scale module development and testing

The team now plans to scale up to produce and test a full-size module with an area of 2.8 m² in the coming months. They hope to achieve an efficiency of about 18% to 19% for this larger solar module. This work is part of UNSW’s industry partnership with UtmoLight, announced earlier this year.

UtmoLight unveiled a 2.8 m² module rated at 450W with 16.1% full-area efficiency in November 2024. The company has started what it calls China’s first gigawatt-scale production line for such technology. The full-capacity output of that line is about 1.8 million modules a year. Hao stated that testing ideas for upscalability helps industry identify innovations for large-scale processing.

Broader context in UNSW’s renewable energy research portfolio

This perovskite work complements Hao’s broader research on alternative photovoltaic materials like kesterite and on tandem technologies. The Australian Renewable Energy Agency (ARENA) recently announced up to AU$105.6 million for 20 solar research and development projects, describing it as its largest single solar PV research investment. From that funding, Hao received AU$6.3 million for a project to make perovskite-silicon tandem panels more efficient and reliable. UNSW also received AU$5.6 million to field test commercial perovskite and tandem modules for stability.

Hao has distinguished her team’s kesterite work from much of the perovskite field. She stated that perovskite research has often pursued high efficiency first and addressed stability afterwards, whereas her group starts with an abundant, environmentally friendly, and stable material. She expects silicon to remain the dominant PV technology, with perovskites and kesterite finding their clearest opportunity in tandem cells.

Statements on research philosophy and industrial translation

Hao emphasized that the goal extends beyond efficiency records to developing reliable, scalable designs. Our focus is therefore not simply on finding high-performance materials, but on understanding how to design materials and interfaces that remain effective under the conditions required for large-area fabrication, she said. This approach is also beneficial for industry, as it helps identify innovations that can overcome limitations in large-scale processing systems.

Dr Zhen Li and Dr Ziyue Feng were part of the UNSW team involved in the research. UtmoLight contributed expertise in large-area processing and module fabrication. Despite the promising result, UNSW said further work is needed on efficiency, reproducibility and long-term stability before wide deployment. The team plans to produce and test a full-size perovskite module with an area of 2.8 m² in the coming months, targeting 18-19% efficiency.