Waterproof Cesium Lead Bromide Perovskite Lasers and Their Applications in Solution

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Lead halide perovskites possess excellent optoelectronic properties, making them suitable for solar cells and light sources.
• The solubility of lead halide perovskites in polar solvents limits their practical applications.
• Effective protection against polar solvents is crucial for the stability and utility of perovskite materials.

Purpose of the Study:

• To develop a method for protecting cesium lead bromide (CsPbBr3) nanoplate (NP) lasers from polar solvents.
• To investigate the lasing behavior of protected CsPbBr3 NPs in varying refractive index environments.
• To explore the potential of these protected NP lasers for sensing applications.

Main Methods:

• Coating CsPbBr3 NPs with atomic layer deposition (ALD) aluminum oxide (Al2O3) to create a waterproof layer.
• Testing the continuous lasing performance of Al2O3-coated CsPbBr3 NPs in water over extended periods.
• Studying the lasing characteristics (mode selection, threshold) of protected NPs in mixed water-glycerine solutions with varying refractive indices.

Main Results:

• Al2O3-coated CsPbBr3 NPs demonstrated continuous lasing in water for over an hour and remained functional after a month of immersion.
• The NP laser exhibited mode selection phenomena (single-mode to dual-mode and back) as the environmental refractive index increased.
• Lasing thresholds increased with the environmental refractive index, enabling refractive index sensing with high sensitivity (129.7 μJ cm⁻² RIU⁻¹ for long-wavelength mode).

Conclusions:

• ALD Al2O3 provides effective protection for CsPbBr3 against polar solvents, significantly enhancing material stability.
• The protected CsPbBr3 NP laser shows tunable lasing behavior and potential for sensitive environmental sensing.
• This protection strategy enables the integration of perovskite lasers into on-chip devices and various solvent-based systems.