Group IV semiconductor quantum dots have gained noteworthy interest in optoelectronic applications owing to their high natural abundance, low-cost of elemental components, and lack of toxicity. A number of chemical syntheses for colloidal Si and Ge quantum dots have been reported and new methods continue to appear. However, these methods generally lack the wide tunability of particle size and consequently absorption and emission energies resulting in minimal exploration of their photophysical properties. To address this issue, we have recently studied the incorporation of elemental Sn into Si and Ge, to produce homogeneous Ge1-xSnx and Ge1-x-ySixSny alloy quantum dots, displaying composition-tunable absorption and high-intensity photoluminescence throughout much of the visible to near infrared spectrum. Herein the physical and photophysical characterization of Ge1-xSnx and Ge1-x-ySixSny alloy quantum dots using powder X-ray diffraction, transmission and scanning electron microscopy, energy dispersive spectroscopy, steady state and time-resolved absorption and emission spectroscopy and first-principles simulations will be reported. The effect of synthetic parameters on primary particle size, morphology, composition, fundamental electronic structure, and absorption and emission energy will be discussed in light of their application in visible to near infrared optoelectronics.

Colloidal synthesis, energy gap tuning, and carrier dynamics of GeSiSn alloy quantum dots with visible to near IR photoluminescence

256th National Meeting (2018)

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