Surface passivation dependent photoluminescence from silicon quantum dot phosphors

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Development of novel phosphor materials is crucial for advancing lighting technologies.
• Silicon quantum dots (SiQDs) offer potential due to their tunable optical properties and non-toxic nature.

Purpose of the Study:

• To synthesize and characterize wavelength-tunable, air-stable, and non-toxic phosphor materials utilizing silicon quantum dots (SiQDs).
• To explore the potential of these SiQD-based phosphors for general lighting applications.

Main Methods:

• Synthesis of micrometer-size silicon particles with attached SiQDs using electrochemical etching under ambient conditions.
• Characterization of photoluminescence (PL) properties, including peak wavelength tunability and quantum yield.
• Demonstration of SiQD-phosphor integration into polymers for LED excitation.

Main Results:

• Achieved wavelength-tunable phosphors based on SiQDs, exhibiting air stability and non-toxicity.
• Controlled the PL peak wavelength by varying SiQD size and surface passivation chemistry.
• Demonstrated a red-emitting phosphor with a 17% photoluminescence quantum yield.
• Successfully embedded SiQD-phosphors in polymers for excitation with 405 nm LEDs.

Conclusions:

• Silicon quantum dot-based phosphors are promising for tunable, stable, and safe lighting solutions.
• Electrochemical etching provides a viable method for synthesizing these advanced phosphor materials.
• The developed SiQD-phosphors show potential for efficient use in general lighting systems.