Next-generation, energy-efficient, ultrafast photosensors and optoelectronics

As Moore’s Law scaling approaches its physical and thermal limits, further performance gains from transistor miniaturisation are becoming increasingly difficult to achieve. The continuous demand for faster, smaller, and more energy-efficient electronic devices, driven by applications in artificial intelligence (AI), wearable electronics, autonomous systems, and real-time environmental monitoring, cannot be met by conventional silicon-based technology alone. Optoelectronic devices, which exploit photon-based information processing and transfer, offer a promising alternative by directly converting light into electrical signals or mechanical responses. At the materials level, light–matter interactions such as photostriction and the bulk photovoltaic effect allow the direct conversion of photon energy into electrical or mechanical responses. These effects underpin the development of compact, high-speed, and low-power optical communication systems, highly sensitive photodetectors, and non-volatile optical memory technologies. The potential applications of such devices are extensive and societally transformative. In healthcare, they could enable portable diagnostic devices capable of detecting biomarkers in real-time, allowing early identification of disease in remote or underserved communities. In transportation, integrating these materials into autonomous vehicle sensors provides ultra-fast optical readout for collision avoidance and route optimization, improving both safety and efficiency. In environmental management, optoelectronic sensors can measure pollutants or monitor water and soil quality with high spatial and temporal resolution, supporting sustainable resource management and evidence-based policymaking. Economically, the integration of these technologies can reduce energy consumption in data centers, lower the cost of AI computing, and open new markets for wearable electronics, neuromorphic computing hardware, and autonomous systems, generating both industrial growth and employment opportunities.

Despite these advantages, current material limitations restrict practical implementation. Specifically, traditional semiconductors such as silicon and germanium exhibit relatively weak photostrictive responses and lack switchable polarization for ultrafast responses. Alternative materials such as halide perovskites and lead-based PLZT suffer from toxicity and stability issues, making them unsuitable for scalable, environmentally sustainable production. Therefore, there is an urgent need to develop novel functional materials that combine strong electro-optic performance, environmental safety, and scalability, enabling post-CMOS low-energy transformative nanoelectronics.

In my recent research, published in Adv. Funct. Mater. and ACS Nano (2025, impact factor >16), I developed an advanced BiFeO₃-based ferroelectric material system fabricated through a low-cost solution-processed method that exhibits strong photostrictive responses and light matter interactions that surpass best-performing halide perovskite materials, which are limited by their poor stability and toxicity. In addition, this new system achieves light-modulated, switchable polarization, which is essential for optical communication and imaging technologies. Overall, my works build the foundation for next-generation optoelectronic devices, including high-speed photosensors and energy-efficient optoelectronic memory elements. These works thus establish my leading-edge research in this field, and the proposed project intends to build on these previous investigations, which will eventually form the basis and core of my DECRA application.

In this project, I will take the next step toward developing functional heterostructures of ferroelectric oxides and BiFeO₃-based thin films that has the potential to enable ultrafast and optical control of polarization using polarized low energy visible radiation. Achieving this level of control would allow non-contact, low-energy operation and open a pathway toward all-optical writing and erasing in ferroelectric-based devices. The main aim of the project, using the functional heterostructure, is to achieve, high-performance photonic interconnects and devices that can overcome key limitations of conventional electronic data transmission, such as resistive heating, RC delay, and interconnect bandwidth constraints. In current CMOS-based systems, signal propagation and power dissipation increasingly limit speed and device density. By shifting from electron-based charge transport to photon-based information transfer, the proposed project aims to reduce energy loss and increase data throughput, particularly for short-range, on-chip, and chip-to-chip communication.

To achieve this, I will engineer novel heterostructure materials systems with large spontaneous polarization and strong light–matter interaction. In particular, I will focus on developing materials/heterostructures that exhibit pronounced photostriction and bulk photovoltaic effects. Photostriction, light-induced strain, provides a direct route to optomechanical actuation. The bulk photovoltaic effect, which can generate above-bandgap photovoltages in non-centrosymmetric materials, allows direct conversion of light into electrical signals without p–n junctions. By combining giant polarization with these photon-driven functionalities, it will be possible to realise fast, energy-efficient optoelectronic control of memory elements, logic units, sensors, and imaging devices. Such capabilities are highly relevant to emerging technologies. For example, ultrafast optical switching can improve data processing speed in artificial intelligence hardware; low-power optoelectronic memory can reduce energy consumption in large-scale data centres; and light-driven sensing and imaging platforms can enhance biomedical diagnostics and telecommunication systems. Through materials design, interface engineering, and advanced, correlated characterisation, this project aims to establish a new materials foundation for light-controlled electronics and optomechanical devices that can drive transformative advances across computing, communication, healthcare, and life sciences.