Controlling and Optimizing Amplified Spontaneous Emission in Perovskites

Area of Science:

• Materials Science
• Optoelectronics
• Photonics

Background:

• Perovskites are promising wavelength-tunable laser materials.
• Amplified spontaneous emission (ASE) in optically pumped perovskites shows low thresholds.
• Achieving electrically pumped perovskite lasers requires further investigation.

Purpose of the Study:

• Investigate optical aspects of perovskite ASE for material and device design principles.
• Identify key parameters influencing ASE quality.
• Develop a model for understanding ASE in perovskites.

Main Methods:

• Comparative study of solution-processed and vacuum-deposited CsPbBr3 perovskites.
• Measurement of amplified spontaneous emission (ASE) thresholds.
• Spatially resolved photoluminescence to determine optical loss (Rloss).
• Development of a comprehensive model relating ASE, gain length, optical loss, temperature, and density of states.

Main Results:

• Vacuum deposition yielded superior ASE with a threshold of 35 μJ/cm2.
• Optical loss (Rloss) was significantly lower in vacuum-deposited (40 cm-1) vs. solution-processed (>1000 cm-1) perovskites.
• Demonstrated ASE in perovskite samples with metal electrodes, mimicking diode architecture.
• Identified optical spacer layers as crucial for preventing metal absorption loss.

Conclusions:

• Optical loss is a critical parameter for high-quality perovskite ASE.
• Vacuum deposition offers superior ASE characteristics for perovskite materials.
• A comprehensive model aids in understanding and optimizing perovskite-based laser devices.
• Demonstrated feasibility of electrical pumping through diode architecture with optimized material processing and device design.