Optically Tunable Threshold Switching and Thermally Activated Transport in Planar Ag/MAPbI₃ Thin Single-Crystal...

Area of Science:

• Optoelectronics
• Materials Science
• Solid-State Physics

Background:

• Halide perovskites are advanced optoelectronic materials with mixed ionic-electronic conduction.
• This property, once a stability concern, is now explored for memory and neuromorphic applications.
• Single crystals minimize disruptive grain boundaries, allowing intrinsic property study.

Purpose of the Study:

• To grow methylammonium lead iodide (MAPbI₃) single crystals.
• To fabricate and characterize two-terminal devices using these crystals.
• To investigate the role of interfaces and ionic transport in device performance.

Main Methods:

• Space-confined growth of thin MAPB₃ single crystals.
• Fabrication of planar devices with silver (Ag) contacts.
• Electrical characterization (I-V curves) under varying light and temperature conditions.
• Analysis using Schottky-diode models and control devices.

Main Results:

• Devices showed ultra-low dark currents (10^-13–10^-12 A) and minimal dark hysteresis.
• Under illumination, devices exhibited polarity-dependent hysteresis and threshold switching.
• Temperature-dependent studies revealed contact-influenced, thermionically activated transport.

Conclusions:

• Silver-perovskite interfaces significantly influence device transport properties.
• The observed hysteresis is attributed to coupled interfacial and ionic processes.
• MAPbI₃ single crystals offer a platform for exploring light-modulated electronic functionalities.