IISER Pune Uses Bismuth Oxyselenide To Create Ultra-Thin, Flexible Electronic Devices

A team of physicists at the Indian Institute of Science Education and Research Pune (IISER Pune) has developed ultra-thin electronic devices using a special semiconductor material called bismuth oxyselenide (Bi₂O₂Se), which has opened new possibilities to make flexible smartphones, wearable health monitors, smart textiles, and bendable electronic gadgets.

The findings were published in the international journal Small, which shows how atom-thin materials can be engineered into durable, high-performance electronic components.

As modern electronics continue to shrink in size while increasing in power, conventional semiconductor materials are approaching their physical limits. This has pushed researchers to explore a new class of materials known as two-dimensional (2D) materials, which are only a few atoms thick. At just a few billionths of a meter thick, which is far thinner than a human hair, bismuth oxyselenide (Bi₂O₂Se) stands out for its potential to enable faster, more efficient, and flexible devices.

However, the widespread use of such 2D materials has been hindered by challenges in producing them at large scale while maintaining stability, speed, and mechanical strength.

In the latest study, led by Prof. Atikur Rahman from the Department of Physics at IISER Pune, the research team developed a simple and effective method to grow large, ultra-thin nanosheets of Bi₂O₂Se while keeping them only a few atomic layers thick. The breakthrough was achieved by carefully optimising critical parameters such as temperature, gas flow rate, precursor ratio, and reaction time.

Using these nanosheets, the researchers have fabricated microscopic electronic devices nearly a thousand times thinner than a human hair. The devices were built on a flexible, plastic-like Kapton substrate and subjected to repeated bending and folding tests.

Even after thousands of bending cycles, the devices showed no degradation in their electrical or light-sensing performance.

“This high level of durability is crucial for future technologies such as smartwatches, foldable displays, and wearable medical sensors, where electronic components must remain reliable despite constant movement and strain,” Prof. Rahman said.

The research was supported by a grant from DST-SERB. The team included Avinash Mahapatra, Sudipta Majumder, H.L. Pradeepa, Pawan Kumar Gupta, Shrikrishna Bhagwat, Shivprasad Patil, and Prof. Atikur Rahman.

The study is titled “Large-Area Bi₂O₂Se Nanosheets With Enhanced Optoelectronic Performance for Flexible Electronics” and highlights a significant step toward the development of next-generation flexible electronics.