A novel low-cost polymer developed by a research team at Zhengzhou University has achieved an unprecedented 19.96% power conversion efficiency in organic solar cells (OSCs). This marks a significant leap forward for sustainable and affordable energy.
“The exorbitant price of photoactive materials is a huge challenge for the industrialization of organic solar cells (OSCs),” remarked a new study.
This breakthrough promises to dramatically reduce the cost of solar energy and accelerate its widespread adoption.
Led by Prof. Chenkai Sun, the team introduced two novel polymers, PTQ14 and PTQ15, which incorporate a trifluoromethyl (CF₃) group to boost performance and drastically slash production expenses.
The economic advantage of PTQ15 is substantial. Its production cost is estimated at just $35,528 per kilogram. This figure is a staggering five to six times less expensive than other high-performance “star” polymers currently on the market, such as PM6 ($205,725/kg) and D18 ($211,432/kg).
The groundbreaking combination of low cost, high efficiency, enhanced stability, and air-process compatibility offered by PTQ15 could be the catalyst needed to transition organic solar cells from laboratory curiosities to a mainstream energy solution.
Polymer breakthrough
This remarkable cost reduction was achieved through a streamlined synthesis process, which required only 3-4 steps and demonstrated impressive yields exceeding 80%.
Beyond its cost-effectiveness, PTQ15 has set a new efficiency benchmark for low-cost organic materials. OSCs utilizing PTQ15 paired with acceptors K1/K6 achieved a record-breaking 19.96% power conversion efficiency.
The research also revealed ultrafast charge transfer at 1.40 picoseconds and minimal non-radiative energy loss, at just 0.190 eV, which indicates exceptional material properties.
“Remarkably, the PTQ15-based ternary OSCs achieve ultrafast and efficient charge transfer within 1.40 ps, significantly faster than their counterparts (14.54 and 10.17 ps),” added the researchers.
Crucially for industrial scalability, the devices maintained an impressive 19.37% efficiency when processed in open-air conditions (25% relative humidity).
“An impressive efficiency of 19.96% is achieved, which is the highest value of OSCs based on low-cost organic photovoltaic materials, and a record efficiency of 19.37% for open-air processed OSCs is also obtained,” the researchers said in a new study.
Industrial scalability, economic promise
This demonstrates a critical step towards large-scale, cost-effective manufacturing.
Their estimated minimum sustainable price is the lowest reported for organic photovoltaics, making them highly competitive with traditional solar technologies.
“This device shows high cost-effectiveness for industrialization with the low minimum sustainable price of only $0.36 per watt,” explained the study.
For years, the commercial industry has been using expensive and complex materials.
The Zhengzho has hampered the commercialization of high-efficiency OSC. The OSC University of Science and Technology team, with collaborators from the Institute of Chemistry, Chinese Academy of Sciences, and Wuhan University, is now focused on further optimizing the technology. Their next goal is to push efficiency beyond 20%.
