InAs/GaAs quantum-dot lasers grown on on-axis Si (001) without dislocation filter layers
Yongli Wang, Bojie Ma, Jian Li, Zhuoliang Liu, Chen Jiang, Chuanchuan Li, Hao Liu, Yidong Zhang, Yang Zhang, Qi Wang, Xinyu Xie, Xiaolang Qiu, Xiaomin Ren, Xin Wei
Abstract
InAs/GaAs quantum dot (QD) laser monolithically grown on silicon is one of the potential approaches to realizing silicon-based light sources. However, the mismatch between GaAs and Si generates a high density of threading dislocations (TDs) and antiphase boundaries (APBs), which trap carriers and adversely affect device performance. In this paper, we present a simple method to reduce the threading dislocation density (TDD) merely through GaAs buffer, eliminating the intricate dislocation filter layers (DFLs) as well as any intermediate buffer layers whose compositions are different from the target GaAs. An APB-free epitaxial 2.5 µm GaAs film was grown on exact Si (001) by metalorganic chemical vapor deposition (MOCVD) with a TDD of 9.4 × 10 6 cm −2 . InAs/GaAs QDs with a density of 5.2 × 10 10 cm −2 were grown on this GaAs/Si (001) virtual substrate by molecular beam epitaxy (MBE) system. The fabricated QD laser has achieved a single facet room temperature continuous-wave output power of 138 mW with a threshold current density of 397 A/cm 2 and a lasing wavelength of 1306 nm. In this work, we propose a simplified method to fabricate high-power QD lasers, which is expected to promote the application of photonic integrated circuits.