Lasing from dot-in-rod nanocrystals in planar polymer microcavities

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Colloidal nanocrystals offer high fluorescence quantum yield and tunable emission for light-emitting devices.
• Integrating nanocrystals with polymer microcavities enables solution-based fabrication of plastic lasers and flexible optoelectronics.

Purpose of the Study:

• To demonstrate lasing from polymer microcavities embedding solution-processable dot-in-rod (DiR) CdSe/CdS nanocrystals.
• To develop a cost-effective fabrication method for plastic laser cavities.

Main Methods:

• Fabrication of polymer dielectric mirrors using spin-coating of polyacrylic acid and poly(N-vinyl carbazole).
• Tailoring the photonic band gap of the mirrors to match the emission spectrum of DiR nanocrystals.
• Embedding DiR nanocrystals within the polymer microcavity via drop-casting and mirror pressing.

Main Results:

• Achieved excellent overlap between the amplified spontaneous emission (ASE) band of DiRs and the cavity's photonic band gap.
• Observed optically pumped lasing at 640 nm.
• Demonstrated a low lasing threshold of approximately 50 μJ cm⁻².

Conclusions:

• Solution-processable DiR nanocrystals can effectively function as gain media in polymer microcavities.
• This approach offers a viable route for fabricating plastic laser cavities and flexible optoelectronic devices.
• The results highlight the potential for advanced applications in smart lighting and sensing technologies.