In a landmark achievement that could reshape the renewable energy landscape, a team of Chinese researchers has developed a new type of solar cell with groundbreaking efficiency, unprecedented stability and an extended service life. The technology could also reduce energy costs to a quarter of that of current silicon-based solar cells, according to the team. The new solar cells use perovskite, a low-cost, easily available inorganic material. When exposed to sunlight, perovskite converts solar energy into electricity in a similar way to traditional solar panels, but with higher efficiency.
While perovskite solar cells (PSCs) have long shown promise for surpassing the efficiency limits of silicon-based cells, their thermal and chemical stability have been problematic. Typically, they degrade rapidly when exposed to oxygen and moisture or when operated at high temperatures. The newly developed perovskite solar cell has a power conversion efficiency (PCE) of 25.6%. Impressively, the cell retains over 90% of its initial efficiency after 1,200 hours of operation at 65 degrees Celsius. The research, spearheaded by Professor Zhu Zonglong from City University of Hong Kong, in collaboration with Li Zhongan from Huazhong University of Science and Technology, was published on October 20 in the peer-reviewed journal Science. “Our study provides theoretical guidance for the design of efficient and stable PSCs and paves the path for easy access to commercially available PSCs,” the team said in the paper.
The team’s breakthrough lies in the improvement of an interfacial layer between the photoactive layer and the anode of the solar cell. Previous studies found using self-assembled monolayers (SAMs) as an interfacial layer generally raises the PCE to above 25%. However, with the monomolecular structure, SAM is only 1-2 nm thick and is easily decomposed at high temperatures. “We designed the SAM in a unique three-dimensional structure and anchored it to a stable nickel oxide film to enhance both thermal and chemical stability. This development effectively boosts the cell’s lifetime performance and energy conversion capabilities,” Zhu said. “Although the lab-tested devices are relatively small, the fabrication methods are simple and highly scalable, indicating suitability for large-scale production. We estimate that the Levelised Cost of Electricity (LCOE) for our new solar cells could be as low as USD5.45 per MWh, significantly lower than the USD24 per MWh for silicon-based solar cells,” he said.
China is already a leader in the photovoltaic (PV) industry, exporting more than four billion solar cells in 2022, with a total export value of USD46.38 billion, according to Customs data. The Chinese PV industry’s global market share exceeds 80% in all aspects, from raw materials to production equipment, according to the China Photovoltaic Industry Association (CPIA) website. “The global energy landscape is shifting to prioritize solar and wind power. Solar power has become the cheapest energy source worldwide with costs dropping over 90% in the past decade. China’s solar industry is willing to make more efforts to address climate change and boost economic growth,” CPIA Spokesman Liu Yiyang said in August, as reported by the South China Morning Post.
