Enhancing the optoelectronic properties of SnS via mixed-phase heterostructure engineering

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Tin sulfide (SnS) shows promise for optoelectronic applications, particularly in photovoltaic devices, due to its excellent electronic and optical properties.
• However, SnS suffers from limited structural instability and oxidation, which create defect states and hinder practical applications.

Purpose of the Study:

• To propose and investigate a mixed-phase SnS/h-BN heterostructure.
• To enhance the chemical and thermal stability of SnS while preserving its optoelectronic properties.
• To explore the potential of this heterostructure for advanced optoelectronic devices.

Main Methods:

• Utilized density functional theory (DFT) and Green's function with screened Coulomb potential (GW) calculations.
• Performed ab initio molecular dynamics simulations to assess thermal stability.
• Analyzed binding energies and band alignment of the SnS/h-BN heterostructure.

Main Results:

• The SnS/h-BN heterostructure demonstrated high structural and thermal stability up to 600 K, confirmed by high negative binding energy and simulations.
• Calculated an indirect DFT band gap of 1.38 eV, corrected to 2.20 eV via GW calculations, indicating suitability for light absorption.
• Observed a type-I band alignment and a vertical intralayer electric field that reduces exciton binding energies, promoting effective charge separation and transport.

Conclusions:

• The SnS/h-BN heterostructure effectively combines the light-harvesting ability of SnS with the stability of h-BN.
• Enhanced charge transport, prolonged recombination lifetime, and improved stability make this heterostructure a promising candidate for next-generation photovoltaic devices.