Optoelectronic devices, such as infrared sensors and LED displays, are the backbone of modern technologies, from medical imaging to smartphone screens. Traditionally, integrating these devices with silicon circuits involves complex methods like flip-chip bonding, which can be costly and prone to alignment errors. Lead-based semiconductors have been emerged as promising candidates. Given the characteristics of their production methods, now, a team led by Professor Jiang Tang at Huazhong University of Science and Technology (HUST), China, has introduced a transformative solution: monolithic synchronous integration. This allows lead-based materials, such as lead sulfide (PbS) and lead-halide perovskites (LHP) films, to be directly grown on silicon circuits in a single, streamlined process, eliminating the need for pre-synthesized materials or separate assembly steps.

Detailed in their perspective, “Recent Advances in Monolithic Integrated Lead-Based Optoelectronic Devices,” published in Frontiers of Optoelectronics, this approach leverages low-temperature processes like spin-coating, chemical liquid-phase deposition, and vapor-phase deposition to create devices that are both high-performing and compatible with existing silicon manufacturing. For example, PbS CQD image sensors, integrated onto readout circuits via spin-coating of pre-synthesized quantum dot inks, achieve resolutions of 40 lp/mm and detect light from X-ray to near-infrared, rivaling costly III-V semiconductors. These sensors could enhance applications like night vision and medical diagnostics. Similarly, lead-halide perovskite displays made via spin-coating of precursor solutions, with an external quantum efficiency of 23.3% at 1000 cd m⁻², showcasing vibrant red, green, and blue emissions. With a further step, the solid-state thin film of active layer could be directly deposited onto the readout circuits by vapour-phase evaporation and liquid-phase deposition. For example, the vapour-phase deposition of perovskite thin films produced active-matrix perovskite LEDs with uniform brightness, resolutions up to 1080 × 2400 and pixel yields of 98.9%, offer bright, tunable colors ideal for next-generation display devices. By eliminating the need for pre-synthesized materials, this method reduces manufacturing complexity and enhances scalability, making it a transformative solution for high-resolution displays in applications like wearable electronics and augmented reality. This could also be potentially realized in the lead sulfide image sensors.

The power of monolithic synchronous integration lies in its ability to simplify production while maintaining high performance. By forming active layers in situ on silicon circuits, it reduces manufacturing complexity, lowers costs, and improves device reliability. Moreover, this method has advantages of versatility and conformality. This enable semiconductor film fabrication on non-planar surfaces, which is a key challenge in the fabrication of biomimetic optoelectronic devices. Therefore, this method opens the door to compact, efficient systems for industries ranging from healthcare to telecommunications. However, challenges like material instability and lead toxicity remain. The team highlights solutions such as advanced encapsulation, which reduces lead leakage to below 5 ppm, and surface passivation to boost stability. They also point to emerging lead-free alternatives, like silver telluride CQDs, which offer promising performance with better environmental safety.

Professor Tang’s team at HUST’s Wuhan National Laboratory for Optoelectronics is pushing the boundaries of optoelectronic integration. Supported by the National Key Research and Development Program of China, their work builds on decades of innovation to make advanced technology more accessible. Monolithic synchronous integration could transform how we produce sensors and displays, paving the way for smarter, more sustainable devices in our daily lives.
DOI:https://doi.org/10.1007/s12200-025-00158-2