Tunable Electronic Transport in Pd$_3$O$_2$Cl$_2$ Kagome Bilayers: Interplay of Stacking Configuration and Strain

TL;DR

This study explores how stacking configurations and strain influence the electronic properties of Pd$_3$O$_2$Cl$_2$ kagome bilayers, revealing tunable band gaps and carrier masses for potential quantum device applications.

Contribution

It provides a comprehensive first-principles analysis of stacking and strain effects on Pd$_3$O$_2$Cl$_2$ bilayers, highlighting their tunable electronic properties and stability.

Findings

Band gap varies from 0.08 to 0.76 eV depending on stacking.

AB$'$ stacking is the most thermodynamically stable.

Strain causes non-monotonic band gap changes and affects carrier masses.

Abstract

Kagome lattice bilayers offer unique opportunities for engineering electronic properties through interlayer stacking and strain. We report a comprehensive first-principles study of Pd$_3$O$_2$Cl$_2$ kagome bilayers, examining four stacking configurations (AA, AA$'$, AB, AB$'$). Our calculations reveal dramatic stacking-dependent band gap modulation from 0.08 to 0.76~eV, with the AB$'$ configuration being the most thermodynamically stable. All stackings exhibit robust mechanical stability with Young's moduli of 54.82-61.97~N/m and ductile behavior suitable for flexible electronics. Carrier effective masses show significant stacking dependence, ranging from 2.39-6.35~$m_0$ for electrons and 0.67-1.55~$m_0$ for holes. Strain engineering of the AB$'$ bilayer demonstrates non-monotonic band gap tuning and asymmetric modulation of carrier masses, with hole effective masses showing stronger strain sensitivity. These results establish Pd$_3$O$_2$Cl$_2$ bilayers as a promising platform for strain-engineered kagome-based quantum devices, where stacking order and mechanical deformation provide complementary control over electronic transport.