Hysteresis in Perovskite Devices: Understanding the Abrupt Resistive Switching Mechanism

Area of Science:

• Materials Science
• Solid-State Physics
• Device Physics

Background:

• Halide perovskite devices show varied current-voltage (I-V) hysteresis, impacting performance.
• Understanding these behaviors is key for device optimization.
• Abrupt switching is critical for memristive applications and solar cell stability.

Purpose of the Study:

• To identify and characterize distinct I-V hysteresis behaviors in halide perovskite devices.
• To elucidate the mechanisms underlying abrupt switching.
• To investigate the role of electrode material and interface in hysteresis.

Main Methods:

• Cyclic voltammetry to observe hysteresis.
• Real-time photoluminescence microscopy to study interface modification.
• Conductive Atomic Force Microscopy (C-AFM) and electron microscopy to analyze filaments.
• Transient and impedance measurements for hysteresis mode differentiation.

Main Results:

• Four distinct hysteresis responses were identified: capacitive, inductive, hysteresis-free, and abrupt switching.
• Interfacial modification under bias and illumination transforms inductive to hysteresis-free behavior.
• Abrupt switching occurs due to filament formation bridging electrodes, creating a reversible short circuit.
• Filaments are composed of metallic silver, confirmed by C-AFM and electron microscopy.
• Gold contacts show similar responses but restricted abrupt switching due to less stable filaments.

Conclusions:

• Hysteresis in halide perovskite devices originates from dynamic interfacial processes and filament formation.
• Abrupt switching is linked to reversible short-circuiting via metallic filaments.
• Device performance and stability can be tuned by understanding and controlling these interfacial and filamentary mechanisms.