Hao Chen

Perovskite photovoltaic devices have the potential to achieve ultra-high efficiency and ultra-low-cost solar power generation. However, there remains a significant gap between the realized efficiency of current devices and their theoretical potential.

Hao Chen focuses on high-efficiency, stable perovskite solar cells, enhancing the performance of both single-junction perovskite photovoltaic devices and multi-junction tandem perovskite devices. He addresses critical issues in perovskite optoelectronic devices, such as interfacial losses and instability. Through innovative strategies like interface and composition engineering, he has achieved multiple efficiency breakthroughs in both single-junction and multi-junction all-perovskite tandem cells.

For single-junction perovskite cells, he introduced a dual-site passivation molecule and proposed a “flat passivation” mechanism, effectively reducing interface defects and promoting charge carrier transport. This approach achieved a quasi-steady-state certified efficiency of 26.15% for a small device (0.05cm²), setting a new efficiency record for inverted-structured perovskite cells. He also increased the certified efficiency of 1cm² single-junction devices from 24.3% to 25.2%, promoting the development of large-area perovskite cells.

For all-perovskite tandem cells, he used a field-effect passivation strategy to reduce open-circuit voltage losses in wide-bandgap perovskite cells, achieving a certified efficiency of 26.3% (NREL certified) for a double-junction all-perovskite tandem cell. This is the first tandem device certified by NREL to surpass the efficiency of single-junction perovskite photovoltaic devices. Furthermore, his team discovered a novel mechanism where lattice distortion suppresses light-induced phase separation. They developed a 2.0 eV wide-bandgap perovskite material stable under illumination and fabricated the first certified all-perovskite triple-junction solar cell with an efficiency of 23.3% (NREL certified). His work holds significant implications for advancing the commercial application of perovskite solar cells and contributes to the optimization of global energy structures and sustainable development.