# Interface-engineered MoS2 heterostructures: from construction strategies to energy and photovoltaic applications

## TL;DR

This paper reviews how interface design in MoS2 heterostructures affects performance in optoelectronics and energy devices, emphasizing strategies to optimize interfacial properties for better efficiency.

## Contribution

The paper introduces a 'backward design' framework linking device metrics to interfacial descriptors and actionable engineering strategies for MoS2 heterostructures.

## Key findings

- Device performance in MoS2 heterostructures is governed by interfacial energy-landscape reconstruction and kinetic competition.
- Type-II alignment and built-in fields enhance charge extraction while suppressing recombination in photovoltaic applications.
- Ion-permeable and strain-accommodating interfaces improve charge-storage kinetics and cycling stability.

## Abstract

Two-dimensional MoS2 is a versatile semiconductor for optoelectronic and energy technologies, yet device performance is often constrained not by intrinsic layer properties but by interfacial bottlenecks such as energy-level misalignment, inefficient charge transfer, trap-mediated losses, and contact resistance. Recent progress in MoS2-based heterostructures demonstrates that nominal band diagrams alone are insufficient to predict outcomes; instead, device metrics emerge from a coupled interplay of energy-landscape reconstruction via interfacial dipoles and built-in fields, kinetic competition among charge transfer, recombination and trapping (kCT/krec/ktrap), and parasitic or contact limitations. Building on this mechanism-to-metrics view, this review summarises scalable construction strategies for vertical, lateral and mixed-dimensional MoS2 heterostructures, and organises interface types as actionable design levers spanning band-alignment classes, contact archetypes and bonding motifs. We further formalise a “backward design” route that starts from the target figure of merit, translates it into experimentally verifiable interfacial requirements including band offsets, dipole steps, PL/TA signatures, Rct and contact resistivity, and then selects material pairing and geometry accordingly. To improve comparability beyond case-by-case reporting, a function–coupling–pairing summary and a minimum measurement checklist are provided. Photovoltaic and energy-storage case studies illustrate how Type-II alignment plus built-in fields suppress recombination and enhance extraction, while ion-permeable, strain-accommodating, Fermi-level-tuned interfaces accelerate charge-storage kinetics and stabilise cycling. Finally, we highlight remaining challenges in wafer-scale defect control, quantitative interface metrology, long-term stability and encapsulation, and interoperable data reporting toward manufacturable MoS2 heterostructure technologies.

Device metrics in MoS2 heterostructures are governed by interfacial energy-landscape reconstruction, rate competition (kCT/krec/ktrap) and contact limits. A backward-design map links measurable interface descriptors to practical engineering levers.