White-Light Emission in Zeolitic Imidazolate Framework Glasses.

Area of Science:

• Materials Science
• Solid-State Chemistry
• Photonics

Background:

• Zeolitic imidazolate frameworks (ZIFs) are emerging as a new class of glass formers.
• These materials possess unique photonic functionalities with potential applications in optoelectronics.

Purpose of the Study:

• To discover and characterize broadband white light emission in ZIF-62.
• To explore the influence of a vitrification-pressurization-annealing strategy on ZIF-62's photoluminescence.
• To demonstrate the feasibility of ZIF-62 for white light-emitting diode (LED) applications.

Main Methods:

• A novel vitrification-pressurization-annealing strategy was employed on ZIF-62.
• Structural analyses were conducted to understand the origin of photoluminescence phenomena.
• A white light-emitting diode (LED) was fabricated using optimized ZIF-62 glass.

Main Results:

• Broadband white light emission was achieved in ZIF-62 glass.
• Pressurization enhanced and broadened the visible light emission.
• Annealing above a critical temperature (1.07Tg) induced a significant redshift in emission.
• Photoluminescence quantum yield reached 12.2% after annealing at 1.13Tg.
• The fabricated LED showed a luminous efficacy of 4.2 lm/W and operational stability.

Conclusions:

• The photoluminescence of ZIF-62 can be precisely tailored through annealing and pressurization.
• Annealed ZIF-62 glass is a promising material for developing one-component white LEDs.
• This study highlights the potential of ZIFs in advanced photonic applications.