I. North China Electric Power University: Dopants Solve the Photothermal Stability Dilemma of Perovskite
Perovskite materials are prone to thermal decomposition and ion migration under light irradiation and high-temperature environments, leading to rapid attenuation of battery efficiency — this is a recognized technical bottleneck in the industry. In November 2024, a research team jointly formed by North China Electric Power University and École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland published their research results in the international academic journal Science, providing an innovative solution to this problem.
The core breakthrough of the research team lies in the "dopant regulation" strategy: during the preparation of the perovskite solution, N,N-dimethylchloroenimine was innovatively added as a dopant. This substance can undergo specific interactions with ions inside the perovskite, in-situ generating triazine ions. These triazine ions can form a stable chemical bond structure: on one hand, they firmly "lock" the active ions in the perovskite, inhibiting the disordered migration of ions under light and reducing grain boundary defects caused by ion accumulation; on the other hand, triazine ions can enhance the thermal stability of perovskite crystals, effectively delaying the decomposition rate of the material in high-temperature environments.
This technology directly improves the lifespan of perovskite solar cells. Previously, the efficiency of ordinary perovskite cells often declined significantly after hundreds of hours under high-temperature and light conditions. However, the cells prepared with this dopant show a significantly slower efficiency attenuation rate under the same harsh conditions, laying a key foundation for the transition of perovskite cells from laboratory research to mass production.
II. City University of Hong Kong: New Device Structure Balances Stability and Production Efficiency
In addition to material-level innovations, optimizing the device structure is also an important direction for improving stability. The research team of City University of Hong Kong has developed a new perovskite solar cell structure, which was also published in Science. Through "structural simplification + material upgrading", it has achieved a triple breakthrough in stability, efficiency, and cost.
Traditional perovskite cells consist of multiple independent structures such as a hole transport layer, a perovskite layer, and an electron transport layer. Not only are the production processes complex, but the organic electron transport layers (such as fullerenes) have poor heat resistance and are prone to aging during long-term use. The team from City University of Hong Kong made two major innovations to address this: first, "structural integration" — merging the originally independent hole transport layer and perovskite layer into one. On the premise of not affecting the charge transport performance, this greatly simplifies the production process and reduces manufacturing costs; second, "material replacement" — replacing the electron transport layer with tin dioxide, an inorganic material. Tin dioxide has excellent heat resistance and can resist the damage of high-temperature environments to the device structure. At the same time, the team improved the oxygen vacancy defects of the tin dioxide layer through technical means, further reducing charge recombination losses.
Test data shows that the perovskite solar cells based on this structure have an energy conversion efficiency exceeding 25%. More importantly, they exhibit excellent stability: in strict tests simulating actual working conditions, after continuous operation for 2000 hours, the efficiency can still maintain more than 95% of the initial value, far exceeding the performance of traditional structured cells. Meanwhile, the simplified process provides feasibility for large-scale mass production.
III. Industrial Value of University Research Achievements
The research of North China Electric Power University and City University of Hong Kong provides practical technical solutions for improving the stability of solar cells from two dimensions: "material regulation" and "structural optimization" respectively. The former solves the photothermal instability problem of perovskite materials themselves, extending the battery lifespan from the root; the latter reduces the production threshold while improving stability through structural innovation. Together, they promote perovskite solar cells towards the industrialization goal of "high efficiency, long lifespan, and low cost".
These achievements not only demonstrate the leading role of universities in the field of photovoltaic basic research but also accelerate the application of solar cells in scenarios such as building-integrated photovoltaics and portable energy equipment. For example, perovskite cells with improved stability can be more safely applied to rooftop power-generating glass and outdoor charging equipment, injecting green momentum into the global energy transition.
