Mitigating Electrochemical Degradation in CsPbBr₃ Gamma Detectors by Organic and Inorganic Encapsulation

Area of Science:

• Materials Science
• Semiconductor Physics
• Detector Technology

Background:

• Cesium lead bromide (CsPbBr3) perovskites offer excellent charge transport for radiation detection.
• Long-term stability is limited by electrode-driven decomposition, exacerbated by moisture and oxygen.
• Interfacial degradation pathways hinder practical application of CsPbBr3 detectors.

Purpose of the Study:

• To investigate organic and inorganic encapsulation strategies for CsPbBr3 radiation detectors.
• To evaluate encapsulation's effectiveness as environmental barriers and suppressors of interfacial degradation.
• To advance the stability and operational capabilities of CsPbBr3-based gamma-ray detectors.

Main Methods:

• Atomic Layer Deposition (ALD) of Al2O3 as an inorganic encapsulant.
• Application of organic encapsulants (paraffin wax, polystyrene).
• Evaluation of environmental ingress blocking, ionic diffusion suppression, and operational stability.

Main Results:

• ALD-Al2O3 formed a conformal passivation layer, blocking environmental factors and ionic diffusion.
• Al2O3 encapsulation reduced leakage current and improved energy resolution.
• Organic encapsulants slowed moisture but did not prevent interfacial reactions; wax extended stability to 90 days.
• ALD-Al2O3 enabled stable operation at electric fields exceeding 5 kV cm-1.

Conclusions:

• ALD-Al2O3 effectively suppresses interfacial degradation pathways in CsPbBr3 detectors.
• Inorganic encapsulation with ALD-Al2O3 significantly enhances detector stability and high-field operational capability.
• This work paves the way for the practical deployment of robust CsPbBr3 gamma-ray detectors.