Revealing a practical path to high-performance chiral perovskites
Researchers at the Centre for Nano and Soft Matter Sciences (CeNS) in Bengaluru have unveiled a practical strategy to control the crystallisation of chiral halide perovskite films. The breakthrough addresses a long-standing hurdle: how to grow phase-pure, orientation-controlled chiral films that deliver reliable performance in advanced optoelectronic devices. The findings hold particular promise for circularly polarised light (CPL) detectors, spintronic components, and photonic synapses—technologies at the forefront of quantum sensing and information processing.
Why chirality matters in optoelectronics
Chirality, the property of an object not being superimposable on its mirror image, is ubiquitous in nature—from the double helix of DNA to spiral galaxies. In materials science, chirality enables unique light-mmatter interactions and electron spin dynamics. For optoelectronics, this translates into improved detection of circularly polarised light and enhanced control over spin currents, both critical for next-generation sensors and quantum devices.
From organic limitations to halide perovskite potential
Traditional chiral materials tend to be organic and suffer from poor charge transport. Halide perovskites, by contrast, offer exceptional electronic properties, including strong charge mobility and easily tunable band structures. By combining chiral molecules with low-dimensional halide perovskites, researchers aim to sculpt hybrid materials that marry robust transport with tailored chiroptical responses. The challenge has been achieving consistent crystallisation that yields uniform, phase-pure chiral films with well-aligned crystal axes.
The CeNS crystallisation study: key findings
The CeNS team focused on thin films of methylbenzylammonium copper bromide, specifically the chiral form ((R/S-MBA)₂CuBr₄). Their investigation revealed a clear crystallisation pathway: crystal growth initiates at the air–film interface and proceeds downward toward the substrate. This vertical progression helps explain prior inconsistencies in film quality and provides a tangible target for process control.
Managing impurities and defects
Solvent entrapment during cooling can introduce impurities that degrade the optical and electronic performance of the films. The researchers demonstrated that choosing solvents with suitable volatility and employing vacuum processing can significantly suppress defect formation. This reduces trap states, improves phase purity, and enhances reproducibility across manufacturing runs—a critical factor for scalable device fabrication.
Towards scalable, device-ready chiral perovskites
The practical recipe emerging from this work centers on two pillars: (1) controlling solvent choice to manage crystallisation kinetics and impurity formation, and (2) using vacuum-assisted processing to minimize trapped solvents and defects. Together, these steps enable the production of oriented, phase-pure chiral perovskite films with reliable chiroptical responses. For device engineers, the ability to predictably tune film orientation and chirality is a major step toward efficient CPL detectors, spintronic components, and photonic synapses that operate at scale.
Implications for India’s growing semiconductor footprint
India has been investing in semiconductor research and development to strengthen its position in global quantum technologies and advanced optoelectronics. Advancements like the CeNS crystallisation protocol can accelerate domestic fabrication of next-generation devices. With a dependable method to produce high-quality chiral perovskite films, researchers can prototype and commercialise CPL-based sensors and spintronic devices more rapidly, fostering collaboration between academia and industry.
Looking ahead: challenges and opportunities
While the results are promising, long-term stability under operating conditions remains a key area for future work. Ongoing studies aim to further refine solvent systems, interface engineering, and encapsulation strategies to maintain performance over time. Additionally, expanding the chiral perovskite family beyond MBA-based systems could broaden the range of achievable optical and electronic properties, unlocking new applications in quantum sensing and neuromorphic photonics.
Conclusion
The CeNS discovery offers a practical crystallisation route to oriented, phase-pure chiral perovskite films, marrying the best of organic chirality with the superior charge transport of halide perovskites. As CPL detectors and spintronic devices move from labs to prototypes and beyond, the ability to reliably control film growth will be a foundational enabler for next-generation optoelectronics. This development positions India at the frontier of quantum light-based technologies and signals a broader shift toward scalable, high-performance materials engineering.
