A high-performance all-silicon photodetector enabling telecom-wavelength detection at room temperature

TL;DR

This paper introduces a novel all-silicon photodetector operating at telecom wavelengths, achieving high responsivity and bandwidth at room temperature, facilitating integration into silicon photonic circuits for improved optical communication.

Contribution

We demonstrate a high-performance, all-silicon waveguide-coupled photodetector using deep-level impurities to enable efficient sub-bandgap absorption at 1550 nm, eliminating the need for germanium integration.

Findings

Responsivity of 0.56 A/W at 1550 nm

Bandwidth of 2 GHz achieved

Quantum efficiency of 44.8%

Abstract

Photonic integrated circuits (PICs) are crucial for advancing optical communications, promising substantial gains in data transmission speed, bandwidth, and energy efficiency compared to conventional electronics. Telecom-wavelength photodetectors, operating near 1550 nm, are indispensable in PICs, where they enable the sensitive and low-noise conversion of optical signals to electrical signals for efficient data processing. While silicon is ideal for passive optical components, its limited absorption in the optical telecommunication range (1260-1625 nm) typically necessitates integrating an alternative material, such as germanium, for photodetection - a process that introduces significant fabrication challenges. Here, we present a high-performance, all-silicon waveguide-coupled photodetector, which operates at room temperature within the optical telecom C band. By introducing deep-level impurities into silicon at concentrations close to the solid-solubility limit, we enable efficient sub-bandgap absorption without compromising recombination carrier lifetimes and mobilities. This detector achieves a responsivity of 0.56 A/W, a quantum efficiency of 44.8%, a bandwidth of 2 GHz, and a noise-equivalent power of 4.2E-10 W/Hz1/2 at 1550 nm, fulfilling requirements for telecom applications. Our approach provides a scalable and cost-effective solution for the monolithic integration of telecom-wavelength photodetectors into silicon-based PICs, advancing the development of compact photonic systems for modern communication infrastructures.