Highly Efficient and Stable CdZnSeS/ZnSeS Quantum Dots for Application in White Light-Emitting Diode

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Semiconductor quantum dots (QDs) are advanced luminescent phosphors for next-generation lighting and displays.
• QD-based white light-emitting diodes (WLEDs) show significant potential for display applications.

Purpose of the Study:

• To synthesize novel quaternary/ternary core/shell alloyed CdZnSeS/ZnSeS QDs.
• To evaluate the thermal stability and luminescent properties of these QDs.
• To fabricate and characterize a WLED device using the synthesized QDs.

Main Methods:

• Synthesis of quaternary/ternary core/shell alloyed CdZnSeS/ZnSeS QDs.
• High temperature-dependent experiments (295–433 K) to assess thermal stability.
• Fabrication and performance testing of a QD-based WLED, including measurements of luminous efficiency (LE), external quantum efficiency (EQE), and Commission Internationale de l'éclairage (CIE) coordinates.

Main Results:

• Synthesized CdZnSeS/ZnSeS QDs exhibited high bright emission intensity and good thermal stability.
• The fabricated WLED achieved a luminous efficiency of 28.14 lm/W and an external quantum efficiency of 14.86%.
• The WLED displayed warm, bright sunlight-like color (CIE coordinates 0.305, 0.371) with stable photoluminescence (PL) intensity, LE, EQE, and correlated color temperature (CCT) under luminescence stability testing.

Conclusions:

• The synthesized CdZnSeS/ZnSeS QDs are promising materials for high-performance WLEDs.
• The QD-based WLED demonstrates excellent luminous efficiency, color quality, and operational stability.
• These findings highlight the potential of alloyed core/shell QDs for advanced display and lighting applications.