Mastering Chiral Perovskite Films: India’s Leap Toward Next-Gen Optoelectronics

Chirality — the property of an object that makes it non-superimposable on its mirror image — is ubiquitous in nature, from DNA double helices to spiral galaxies.

Chiral perovskites are emerging as a powerful frontier in advanced optoelectronics, offering unique pathways for light–matter interaction and paving the way for technologies like quantum computing, spintronics, and futuristic light detectors. Recent work by researchers at the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru, has provided critical insights into how these materials crystallize, unlocking the possibility of building high-performance devices with phase-pure chiral perovskite films.

Chirality and Its Role in Materials Science

Chirality — the property of an object that makes it non-superimposable on its mirror image — is ubiquitous in nature, from DNA double helices to spiral galaxies. In material applications, chirality holds the key to extraordinary light–matter interactions. For example, chiral materials can distinguish between left- and right-handed circularly polarized light and influence electron spin. This is especially relevant for building devices such as circularly polarized light (CPL) detectors, spintronic components, and neuromorphic photonic synapses.

Why Perovskites are Game-Changers

Traditionally, most chiral materials studied have been organic in nature. While they can interact with light effectively, their poor electrical conductivity has limited their role in optoelectronic devices. Halide perovskites, on the other hand, bring together strong optical properties with efficient charge transport. When combined with chiral molecules, these low-dimensional halide perovskites can yield chiral perovskites that are both functionally versatile and structurally robust, expanding the horizon for device integration.

The Challenge of Controlled Crystallization

The bottleneck has been producing high-quality, phase-pure chiral perovskite films with controlled crystallization. Without precise control, unwanted impurity phases can form, reducing efficiency and stability. Researchers at CeNS focused on methylbenzylammonium copper bromide ((R/S-MBA)₂CuBr₄) thin films to study this phenomenon in detail.

Their findings revealed that crystallization begins at the air–film interface and progresses downward toward the substrate. However, residual solvent trapped during cooling can give rise to 1D impurity phases, compromising film quality.

Key Breakthroughs from CeNS

• Controlled Solvent Evaporation: By regulating solvent evaporation during processing, the team achieved phase-pure and oriented chiral perovskite films.

• Vacuum Processing: Using vacuum conditions effectively suppressed impurity phases by removing residual solvents.

• Growth Tracking: Over two weeks, the researchers mapped how small grains gradually evolved into larger, well-organized structures, offering a roadmap for reproducible film fabrication.

These strategies directly address the challenge of producing device-ready films with uniformity and orientation — vital for consistent performance in optoelectronic applications.

Towards Future Technologies

The ability to control crystallization in chiral perovskite films means scientists now have a toolkit to design materials for highly specialized roles. Applications in CPL detectors could revolutionize imaging systems, while spintronic devices promise faster and energy-efficient computation. Meanwhile, photonic synapses can bring brain-like computing closer to reality.

With India actively pushing into semiconductor and optoelectronic research, this discovery represents a crucial step in positioning the country at the cutting edge of quantum and light-based technologies. The CeNS team is already moving toward fabricating photodetectors using these films, indicating a clear path from lab discovery to device application.

 

The breakthrough in understanding and controlling chiral perovskite crystallization is more than a scientific milestone — it is a technological springboard. By solving one of the biggest challenges in material fabrication, Indian researchers have opened doors to advanced devices that may soon transform communications, sensing, and computing worldwide.