HKUST develops novel perovskite chiral multiple quantum-well system

A research team led by Prof. LU Haipeng, Professor of the Department of Chemistry at The Hong Kong University of Science and Technology (HKUST), has achieved a major breakthrough in preserving spin information for optoelectronic technologies. The team has developed a perovskite chiral multiple quantum wells systems that maintain spin polarization approximately 300 times longer at room temperature. The study opens new possibilities for future quantum technologies and next-generation spin-based applications. The study was published in the prestigious journal Nature Photonics under the title “Perovskite chiral multiple quantum wells with extended spin lifetime via efficient spin cascade."

Semiconductors underpin modern optoelectronic devices, yet the industry continues to face challenges in improving processing speed while reducing energy consumption. To overcome these limitations, researchers are exploring new approaches, particularly spin-based technologies. However, manipulating spin states at room temperature remains extremely difficult due to the rapid spin decoherence process.

To address these challenges, the HKUST research team developed a novel perovskite chiral multiple quantum-well system that enables an efficient "spin cascade" process. Using a two-step seed-assisted crystallization approach, the team constructed well-oriented quantum wells with varying widths and continuous intrinsic chirality across two-dimensional (n=1), quasi-two-dimensional (n=2, 3, 4, …) and three-dimensional (n=¥) perovskite phases.

The structurally coupled quantum wells establish an energy-gradient and fully chiral environment, generating a series of intermediate spin-polarized states. This unique architecture promotes efficient spin transfer across successive chiral quantum wells while reducing interfacial spin losses and suppressing spin relaxation within the bulk phases. As a result, spin polarization can persist for approximately 5 nanoseconds at room temperature, overcoming the conventional limitation that long-lived spin polarization is typically achievable only at ultralow temperatures.

The prolonged spin polarization enables circularly polarized luminescence with a luminescence dissymmetry factor (g_lum) of up to 1.4 × 10^-2. The materials also demonstrate spin-dependent charge transport with a polarization degree exceeding 80%. Building on these properties, the team developed proof-of-concept applications including efficient X-ray-triggered dissymmetric photopolymerization and high-performance circularly polarized light detection, highlighting the material’s potential for asymmetric photocatalysis and advanced optical sensing.

Reflecting on the significance of the work, Prof. LU remarked, “Our study demonstrates that introducing intrinsic chirality across successive quantum-well phases, together with a graded energy landscape, enables efficient spin transfer and prolonged spin polarization in perovskite semiconductors. This provides a promising platform for spin accumulation and the development of advanced chiroptical and spintronic devices.”