Future IoT sensing: Silvaco simulation of graphene-gated p-i-n photosensor on SOI for blue and ultraviolet light

The Internet of Things (IoT) revolutionizes how devices interact and communicate, creating a vast network of interconnected systems with diverse applications, including healthcare, environmental monitoring, and smart cities. A critical component of these IoT systems is the ability to detect and respond to various environmental stimuli, such as light. In this context, photosensors play a pivotal role, particularly in detecting blue and ultraviolet (UV) light, essential for applications like UV index monitoring, flame detection, and secure communications. This paper proposes a lateral p-i-n photosensor design incorporating a single-layer graphene gate, built using silicon-on-insulator (SOI) technology. The device aims to enhance the detection of blue and ultraviolet light. The sensor achieves a larger depletion region with minimal gate bias voltage by employing a graphene gate, leading to superior quantum efficiency. The photosensor exhibits a photocurrent-to-dark current ratio of 1.6×10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup>, a rise time of 2.2 ns, a fall time of 2.0 ns, and an external quantum efficiency of 51.66%. Leveraging graphene's unique optical and electrical characteristics, this gated structure outperforms conventional alternatives. Its compatibility with modern integrated circuit fabrication techniques makes it a promising candidate for future IoT system integration. Simulations conducted using the Silvaco ATLAS platform, a widely used simulation software for semiconductor device modeling and optimization, provide critical insights into the device's operation. The results demonstrate the potential for superior sensitivity and efficiency in IoT-driven blue and UV light detection.