Defect Engineering in Ge QDs for Light Emission in Si Photonics
Sprache des Vortragstitels:
ECS 2018 Fall Meeting
Sprache des Tagungstitel:
The search for a practical, low-cost and monolithic light source that allows for straightforward implementation on CMOS-based microprocessors and that can be easily coupled to existing active and passive Silicon photonics components is ongoing. In this presentation, we will demonstrate an alternative approach to hybrid III-V on Si and strained bulk group-IV (Ge, GeSn) light emitters. This concept makes use of epitaxially grown Ge quantum dots (QDs) in a defect-free crystalline Si matrix, as they are known since the early nineties. However, we will show that the light emission properties of such Ge/Si QDs can be boosted by intentional, low-dose and low-energy implantation of heavy ions (such as Ge and Si) into the QDs. We demonstrate CMOS-compatible lasing from these novel QDs in which defined point-defects states spatially confine electrons after their tunnelling into the nanostructures. This leads to optically direct transitions and, hence, efficient light emission. In contrast to conventional epitaxial Ge/Si QDs - these defect-enhanced QDs (DEQDs) exhibit dramatically shortened carrier lifetimes and negligible thermal quenching of the photoluminescence above room-temperature (RT). Embedding the DEQDs into microdisk resonators leads to lasing characteristics up to RT upon optical excitation. Contact doping and hence fabrication of electrically driven devices is straightforward in this nanosystem since DEQDs are embedded into a defect-free Si matrix. LEDs containing DEQDs show bright emission up to 100°C, the temperature limit of the measurement setup.
Sprache der Kurzfassung:
Hauptvortrag / Eingeladener Vortrag auf einer Tagung