Quantum nanostructure intermixing for monolithic semiconductor photonic integration.

摘要

Quantum well intermixing (QWI), a postgrowth bandgap engineering technology, has been viewed as a promising method for semiconductor photonics integrated circuits (PICs). In this research, we investigated a novel intermixing process that yields large bandgap blueshift at low activation energy in various quantum well and dot structures using metallic impurity induced disordering technique. Large bandgap selectivity and high intermixed material quality have also been observed from GaAs-based quantum well nanostructures. Impurity-free vacancy induced disordering (IFVD), Cu:SiO2 intermixing and nitrogen (N) ion-implantation induced disordering (N-IID) have been performed to promote the efficient group-III intermixing in InP-based quantum dash laser structure. Using Cu:SiO2 and N-IID to promote universal intermixing on dash-inwell InP-based laser structure, up to a maximum bandgap shift of 208 nm (115 meV) and 193 nm (106 meV) were observed from the Cu:SiO2 and N-IIID intermixed samples, respectively.;Proof-of-concept devices based on the quantum well and quantum dash intermixing developed in this work are demonstrated. The bandgap tuned lasers are fabricated and characterized. The demonstration of intermixed devices is important as it can provide tremendous insight into the technological capabilities of intermixing in regards to the active-passive monolithic and planar integration at a postgrowth level. Bandgap tuned QDash lasers have been fabricated with over 180 and 130 nm wavelength blueshift after Cu:SiO2 and N-IID processed, respectively. The broadband laser emissions at room temperature up to 80 nm wavelength coverage have been demonstrated. The N-IID lasers exhibit higher internal quantum efficiency, lower threshold current density, while the Cu:SiO 2 intermixing process degrades the laser performance. However, larger broad lasing spectra and wavelength tuning were obtained from Cu:SiO 2 lasers. Optimizations of the Cu:SiO2 process have yet to be investigated. Hence, the broadband QDash lasers can be served as a practical, compact, cost effective, long lifetime, and highly efficient emitter well suited for diverse applications in optical communications, spectroscopy, sensing and imaging.