Charge transport mechanisms of PbSnSe2 and observation of transition from direct to Fowler–Nordheim tunneling

Abstract

In this study, we report the observation of various conduction mechanisms in mechanically exfoliated PbSnSe₂ based on temperature-dependent current and voltage characteristics. A transition from direct tunneling to Fowler–Nordheim tunneling in PbSnSe₂ was observed at 2.63 V. At lower temperatures, the 3D Mott variable range hopping model fits the data, yielding a density of states of ∼8.80 × 10²⁰ eV⁻¹ cm⁻³ at 2 V. The values of W_hop and R_hop were 64 meV and 22.7 nm, respectively, at 250 K. The Poole–Frenkel conduction was observed in the Au/PbSnSe₂/Au device and the dielectric constant of PbSnSe₂ was calculated to be 1.4. At intermediate voltages, a space charge limited current with an exponential distribution of traps was observed and a trap density of ∼9.53 × 10¹³ cm⁻³ and a trap characteristic temperature of 430 K were calculated for the Au/PbSnSe₂/Au device.