Extraction of Schottky Diode parameters, Electron Transport and Dielectric Relaxation in PdSe2 nanoflakes

Abstract

Palladium Diselenide (PdSe2 ) exhibits unique anisotropic electronic behavior, high carrier mobility, and a layer-dependent indirect-to-direct bandgap transition, positioning it as a versatile material for next-generation 2D device architectures. In this work, we investigated the electrical properties; conduction and relaxation mechanisms of mechanically exfoliated PdSe 2 flakes.Raman spectroscopy and AFM were employed to confirm purity and thickness of the sample.Electrical characterizations including current-voltage (IV) measurements and complex impedance spectroscopy (CIS) were performed, revealing crucial information about charge carrier transport mechanisms, contact behavior, and resistive properties. For contact-limited conduction mechanisms, Schottky emission was investigated, and the thermionic emission model was employed to determine Schottky diode parameters, along with a re-evaluation of Richardson's constant. In bulk-limited conduction mechanisms, Poole-Frenkel (PF) emission was ascertained with a determination of the dielectric constant. To gain insight into relaxation mechanisms, complex impedance spectroscopy, complex dielectric permittivity, and complex modulus spectroscopy were conducted. A switching ratio of ~10 2 was achieved, indicating the suitability of PdSe 2 for applications in memory devices, neuromorphic computing, and sensing technologies.