Highly Uniform Pyrene-Based Host-Guest-Doped Organic Thin Films with Ultralow ASE Threshold and High Stability

Area of Science:

• Materials Science
• Optoelectronics
• Organic Electronics

Background:

• Organic semiconductor thin-film lasers offer promising applications.
• High-quality organic films are crucial for device efficiency and stability.
• Postgrowth evolution can lead to degradation, causing optical losses.

Purpose of the Study:

• To suppress thin-film failure in organic lasers by controlling postgrowth evolution.
• To enhance the morphological and optical stability of organic thin-film lasers.
• To develop durable organic laser materials with improved performance.

Main Methods:

• Synthesis of two pyrene-based derivatives for a host-guest luminescent system.
• Comparison with a conventional system using CBP as the host material.
• Analysis of temporal evolution of morphological and optical gain properties.

Main Results:

• Both systems achieved high photoluminescence quantum yields and ultralow amplified spontaneous emission (ASE) thresholds (< 1 μJ cm⁻²).
• CBP-based films degraded rapidly due to crystallization and phase separation, losing optical gain.
• Pyrene-based films maintained morphological integrity for over 20 days with only minor microcrystallization, keeping ASE thresholds below 10 μJ cm⁻².

Conclusions:

• The pyrene-based host-guest system demonstrates superior durability compared to CBP-based systems.
• Controlling postgrowth evolution is key to preventing degradation in organic thin films.
• The developed pyrene-based system shows significant potential for stable and efficient organic thin-film lasers.