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 [1-3]. 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 [1-4]. 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) [1]. Embedding the DEQDs into microdisk resonators leads to lasing characteristics up to RT upon optical excitation [3]. 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 [5].

[1] Grydlik, M.; Hackl, F.; Groiss, H.; Glaser, M.; Halilovic, A.; Fromherz, T.; Jantsch, W.; Schäffler, F.; Brehm, M. ACS Photonics 2016, 3 (2), 298–303

[2] Grydlik, M.; Lusk, M. T.; Hackl, F.; Polimeni, A.; Fromherz, T.; Jantsch, W.; Schäffler, F.; Brehm, M. Nano Lett. 2016, 16 (11), 6802–6807

[3] Brehm M. and Grydlik, M. Nanotechnology 2017, 28, 392001

[4] Groiss H., Spindlberger L., Oberhumer P., Schäffler F., Fromherz T., Grydlik M. and Brehm M, Semicond. Sci. Technol. 2017 32 (2), 02LT01

[5] Rauter P., Spindlberger L., Schäffler F., Fromherz T., Freund J., and Brehm M., ACS Photonics 2018, 5 (2), pp 431–438