Enhanced light emission of germanium light-emitting-diode on 150 mm Germanium-on-Insulator (GOI)

• Main Authors: Wu, Shaoteng, Wang, Zhaozhen, Zhang, Lin, Chen, Qimiao, Wen, shuyu, Lee, Kwang Hong, Bao, shuyu, Fan, Weijun, Tan, Chuan Seng, Luo, Jun-Wei
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2023
• Subjects: Engineering::Electrical and electronic engineering::Microelectronics; Germanium; Photodetector; Germanium-on-Insulator
• Online Access: https://hdl.handle.net/10356/167161
• Institution: Nanyang Technological University

Germanium-on-insulator (GOI) has become a novel platform for Ge-based electronic and photonic applications. Discrete photonic devices such as waveguides, photodetectors, modulators, and optical pumping lasers have been successfully demonstrated on this platform. Realize electric injection emitting is highly desirable towards integrated photonics. However, there is almost no report on the electrically injected Ge light source on the GOI platform. In this work, we first fabricate the vertical Ge p-i-n light-emitting-diodes (LEDs) on the 150 mm GOI substrate. The high-quality Ge LED on a 150-mm diameter GOI substrate was fabricated via direct wafer bonding followed by ion implantations. As a tensile strain of 0.19% has been introduced during the GOI fabrication process resulting from the thermal mismatch, the LED devices exhibit a dominant direct bandgap transition peak near 0.785 eV (~1580 nm) at room temperature. In sharp contrast to conventional III-V LEDs, we found that the EL/photoluminescence (PL) spectra show enhanced intensities as raising the temperature from 300 to 450 K as a consequence of the higher occupation of the direct bandgap. The maximum enhancement in EL intensity is a factor of 140% near 1635 nm due to the improved optical confinement offered by the bottom insulator layer. This work potentially broadens the GOI's functional variety for applications in near-infrared sensing, electronics, and photonics.