Breaking a key materials challenge, researchers have tuned perovskite crystallisation on industrial TOPCon silicon and reported record performance for a monolithic tandem device.
What the team achieved
Researchers from JinkoSolar, the National University of Singapore (NUS) and the Solar Energy Research Institute of Singapore (SERIS) developed a perovskite–silicon tandem solar cell that received certification from China’s National Photovoltaic Industry Metrology Test Center. The team reported a certified stabilized efficiency of 32.76%, while a 0.925 cm² test device reached 33.62% under standard test conditions with an open-circuit voltage around 1.97 V.
How the MBT additive controls crystallisation
Instead of focusing only on inorganic ions, the researchers targeted organic cations in the perovskite precursor. They added 2-mercaptobenzothiazole (MBT) to the solution. MBT’s dual binding sites—the heterocyclic nitrogen and the thiol (-SH) group—interact with formamidinium (FA) cations through hydrogen bonding and electrostatic effects. This stabilises intermediate phases and slows crystallisation, producing compact, void-free perovskite films on industrial silicon wafers.
Device structure and testing
The tandem architecture combined an industrial TOPCon silicon bottom cell (Czochralski monocrystalline wafers ~182 mm square, ~130 µm thick) with a perovskite top cell. The perovskite stack included ITO, a nickel oxide hole-transport layer, a self-assembled monolayer, the MBT-treated perovskite absorber, a C60 electron-transport layer, SnO2 and a top ITO contact. Under standard illumination the small-area tandem reached 33.62% PCE; it retained about 91% of initial efficiency after 1,700 hours of continuous maximum-power-point operation at room temperature and 85% relative humidity.
Why this matters
The advance tackles a practical manufacturing barrier: industrial TOPCon wafers transfer heat rapidly during perovskite annealing, often causing uncontrolled crystallisation, voids and defects. By slowing and controlling film formation with a scalable organic additive, the team demonstrated a route to high-efficiency, void-free perovskite layers compatible with existing silicon production lines. That improves prospects for integrating perovskite technology into mainstream high-throughput manufacturing.
Commercial prospects and next steps
- Scalability: The MBT additive is compatible with large-area, solution-processing workflows, which supports translation to industrial roll-to-roll or slot-die processes.
- Durability: Early stability data are promising but larger-area modules and longer-term field testing will be required to confirm commercial readiness.
- Integration: The approach targets standard TOPCon wafers and processes, reducing the need for radical changes to existing factories.
Conclusion
This work demonstrates a practical materials solution to a manufacturing challenge, delivering certified high efficiency for a perovskite–TOPCon tandem and suggesting a clear path for industrial adoption. The results, published in Nature Energy, mark an important step toward more efficient, commercially viable silicon–perovskite tandem photovoltaics.