Abstract
High-performance III–V quantum-dot lasers monolithically grown on Si substrates have been demonstrated as a promising solution to realize Si-based laser sources with very low threshold current density, high output power, and long lifetime, even with relatively high density of defects due to the material dissimilarities between III–Vs and Si. On the other hand, although conventional III–V quantum-well lasers grown on Si have been demonstrated after great efforts worldwide for more than 40 years, their practicality is still a great challenge because of their very high threshold current density and very short lifetime. However, the physical mechanisms behind the superior performance of silicon-based III–V quantum-dot lasers remain unclear. In this paper, we directly compare the performance of a quantum-well and a quantum-dot laser monolithically grown on on-axis Si (001) substrates, both experimentally and theoretically, under the impact of the same density of threading dislocations. A quantum-dot laser grown on a Si substrate with a high operating temperature (105 °C) has been demonstrated with a low threshold current density of 173 A/cm2 and a high single facet output power >100 mW at room temperature, while there is no lasing operation for the quantum-well device at room temperature even at high injection levels. By using a rate equation travelling-wave model, the quantum-dot laser's superior performance compared with its quantum well-based counterpart on Si is theoretically explained in terms of the unique properties of quantum dots, i.e., efficient carrier capture and high thermal energy barriers preventing the carriers from migrating into defect states.
Highlights
SI-BASED photonic integrated circuits (PICs) are expected to meet the demands of the ever growing increase in data traffic by providing an efficient data transmission method via optical interconnects integrated on the Si platform [1]
We have presented a study on the effect of enhanced non-radiative recombination through threading dislocations (TDs) on the performance of InAs/GaAs quantum dots (QDs) and InGaAs/GaAs quantum wells (QWs) lasers monolithically grown on (001) Si in order to explain the much superior performance obtained with InAs/GaAs QD active regions rather than In0.15Ga0.85As/GaAs QWs
An InGaAs/GaAs QW laser with a similar TD density grown on Si substrate under identical conditions showed no lasing behavior at room temperature, confirming the advantages of QDs over QW-based active regions in lasers monolithically grown on Si [42]
Summary
SI-BASED photonic integrated circuits (PICs) are expected to meet the demands of the ever growing increase in data traffic by providing an efficient data transmission method via optical interconnects integrated on the Si platform [1]. InAs/GaAs quantum dots (QDs), on the other hand, have recently been proposed to be a more suitable gain medium for direct growth on Si, showing impressive laser performance in terms of a very low threshold current density of 62.5 Acm-2 and a record lifetime of 3,001,402 hours [16,18,19]. What is more, these QD lasers have demonstrated good lasing characteristics even at high TD densities of the order up to 108 cm-2 [18]. A highly doped p-type GaAs contact layer completed the
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
