New Cost-Effective Silicon-Based Photodiodes for Near-IR Applications

In a groundbreaking project at the Fraunhofer Institute for Photonic Microsystems IPMS, a new era of sensitive silicon-based photodiodes is being ushered in for near-infrared (near-IR) applications. While silicon is the default material for photodiodes in the visible range due to its cost-efficiency, its use in the near-IR spectrum has been limited by low sensitivity, leading to the adoption of materials like indium gallium arsenide (InGaAs) with their own costly manufacturing processes.

However, Fraunhofer IPMS is now pioneering a novel research approach to enhance the sensitivity of low-cost silicon photodiodes in the near-IR. Project coordinator Michael Müller elaborates on the innovation, stating, "Our photodiode design incorporates unique pyramidal and ring structures that act as light collecting basins, departing from the conventional planar topography. By introducing a thin metal layer in the Schottky barrier, we boost the internal quantum efficiency, thereby increasing the generation of charge carriers by light in the semiconductor."

This innovative approach not only promises economic benefits through the utilization of established silicon semiconductor technologies but also aligns with ecological goals by eliminating the need for heavy metals in the manufacturing process. This dual advantage positions the development as a significant stride towards sustainability in the semiconductor industry.

Looking ahead, the enhanced silicon photodiodes hold the potential to unlock a myriad of applications in the near-IR spectrum, particularly in markets that demand cost-effective solutions at scale. For instance, in the realm of autonomous driving, the technology can support the deployment of advanced LiDAR sensors and fog cameras for efficient environmental monitoring, crucial in scenarios where visibility is compromised by smoke or fog, rendering traditional optical cameras ineffective.

Moreover, the implications extend to security technology, spanning from safeguarding critical infrastructure to enhancing security measures in the private sector. The versatility of silicon photodiodes also extends to fields such as chemical and medical imaging, as well as spectroscopy, with near-IR hyperspectral imaging finding utility in process measurement applications within the pharmaceutical and chemical industries for the detection and analysis of organic materials and material mixtures.

For more information on the groundbreaking work being done at Fraunhofer IPMS, visit their official website at www.ipms.fraunhofer.de/en.html.