Unveiling a new path for chiral materials in optoelectronics
Chiral perovskite films are emerging as a key platform for next‑generation optoelectronics. Researchers at the Centre for Nano and Soft Matter Sciences (CeNS) in Bengaluru have demonstrated a practical way to control how these films crystallise, a breakthrough that could unlock high‑performance devices such as circularly polarised light (CPL) detectors, spintronic components, and photonic synapses. By marrying the light‑handling prowess of halide perovskites with the unique handedness of chiral molecules, the team has moved closer to scalable, phase‑pure, oriented films that can be used in real devices.
Why chirality matters in materials science
Chirality describes structures that are not superimposable on their mirror image. In materials, this feature fosters distinctive interactions with light and electron spins, enabling phenomena such as selective detection of circularly polarised light and control over electron spin states. These capabilities are particularly appealing for quantum sensing, spintronics, and neuromorphic photonics—areas that demand precise control over light–matter interactions.
The challenge with chiral materials and halide perovskites
Although many chiral materials are organic and struggle with charge transport, halide perovskites offer excellent electronic properties and tunable chemistry. When chiral components are integrated with low‑dimensional perovskites, the resulting hybrids promise better performance, but controlling crystallisation remains a major hurdle. Achieving uniform, phase‑pure, oriented films is essential for reliable device operation, especially in sensitive optoelectronic applications like CPL detection.
CeNS breakthrough: controlled crystallisation at the nanoscale
The CeNS team investigated thin films of methylbenzylammonium copper bromide, designated as (R/S-MBA)₂CuBr₄. Their key finding is that crystal growth initiates at the air–film interface and progresses toward the substrate. This directional growth offers a tangible handle to tailor film orientation, a critical factor for consistent device performance. The researchers also identified that impurities arise when solvent becomes trapped during cooling, creating defects that can degrade electronic and optical functionality.
Practical recipe for high‑quality chiral perovskite films
To suppress defect formation and promote phase purity, the team highlighted careful solvent selection and vacuum processing during fabrication. By optimizing these steps, it is possible to reduce solvent entrapment and remove impurities, resulting in oriented, high‑quality chiral perovskite layers suitable for scalable manufacturing.
Implications for next‑generation devices
With a reliable method to control crystallisation, chiral perovskite films become more attractive for practical devices. Potential applications include CPL detectors that can selectively respond to circularly polarised light, spintronic components that exploit chiral‑induced spin selectivity, and photonic synapses for neuromorphic computing. The combination of efficient charge transport in halide perovskites with chirality could yield devices that are both fast and energy‑efficient, a valuable proposition for future quantum optoelectronics.
India’s role in advancing quantum optoelectronics
India’s expanding semiconductor and materials science ecosystem provides a fertile ground for translating such fundamental insights into scalable technologies. The CeNS results contribute to a growing national capability in designing and fabricating advanced functional materials, reinforcing India’s position in the vanguard of next‑generation light‑based technologies.
Looking ahead
Beyond CPL detectors, controlled crystallisation of chiral perovskite films could inform the design of spin‑based devices, sensory systems, and energy‑efficient photonic circuits. As researchers refine solvent systems, processing atmospheres, and layer architectures, these materials may become cornerstone components of future quantum and neuromorphic technologies.
