New Record in Perovskite Solar Cell Efficiency by Australian Researchers
Recent research from the University of New South Wales (UNSW) has unveiled significant advancements in perovskite solar cells, but it’s the enigmatic details surrounding a secret molecule that has drawn particular attention. This team, who recently secured a $6.3 million grant, has demonstrated that their perovskite cells can nearly rival the efficiency of traditional silicon solar panels.
Their results indicate a remarkable 23.5 per cent efficiency rating for a specific 30 x 30 cm “submodule” design without any supplementary layers to enhance power output. Led by Scientia Professor Xiaojing Hao, the researchers claim to have achieved a world record that marginally surpasses a similar achievement from a Chinese team using iron compounds.
Secrecy Surrounding New Innovations
While much has been reported about their efficiency, Hao has refrained from divulging critical specifics regarding the methods they utilised to reach this milestone, citing pending patents as the reason for her discretion. What is known is that the team has eliminated a layer of nickel oxide and introduced a novel, yet undisclosed, molecule into their solar cells.
Perovskite cells are typically created from a liquid solution that, upon heating, crystallises into a structure capable of converting sunlight into electricity. An additional metal oxide layer is applied to guide the flow of positive charges and electrons, although this layer also contributes to the degradation of the crystals.
According to Zhen Li, a member of Hao’s group, the newly added molecule serves the same function as the nickel oxide layer but avoids causing the same deterioration. Ensuring even distribution of this molecule within the solution proved challenging, yet Li asserts that the solution to this issue represents one of the key innovations in this latest research.
Pursuing Stability in Perovskite Technology
Despite their promise, perovskite solar cells have faced significant challenges concerning longevity. Indeed, numerous Australian researchers have worked tirelessly over the past decade in pursuit of a stable, commercially viable solution. A recent report suggested that this year, perovskite technology could be a contender at a 2 gigawatt (GW) level in the solar industry.
However, the technology has consistently battled stability challenges, leading to rapid degradation when exposed to heat, moisture, and light. The most efficient crystalline structures often fall victim to this instability, deteriorating swiftly within days or months, and are not scalable beyond lab-sized samples of 1 cm by 1 cm.
Hao acknowledges the ongoing struggle with stability, stating, “While we achieve high efficiency, the main issue remains how to ensure durability.” The research team aims to simultaneously enhance efficiency and stability while also identifying materials that perform well in large-scale production.
Competition in the Renewable Energy Sector
The drive to harness perovskite technology continues, primarily due to its cost-effectiveness and comparatively simpler manufacturing process relative to silicon photovoltaics (PV), which require sophisticated cleanroom environments and high temperatures. In just two years, Hao’s team advanced from a 1 cm² module to the larger 30 cm² version, reflecting the rapid developments in the sector.
While numerous companies dedicated to commercialising perovskite cells are primarily based in China, there are notable exceptions. UK-based Oxford PV operates a factory in Germany, and the Chinese companies Microquanta and GCL Perovskite are both actively advancing perovskite testing and production.
Additionally, the company Utmolight has successfully brought commercial perovskite cells to market and is collaborating with Hao’s team to develop a 2.8 m² module suitable for outdoor use. This partnership is supported by the Australian Renewable Energy Agency (ARENA) grant, which will enable the team to adapt their findings to create tandem cells that integrate both silicon and perovskite technologies.
Perovskite is seen as a vital component in enhancing the efficiency of silicon PV systems, allowing manufacturers to increase solar energy output without proportionately enlarging the panels themselves. The collaboration with Utmolight permits ongoing testing of concepts on a larger scale, which can expedite the development process and focus on viable strategies.
