Halide perovskites: Is it all about the interfaces?

TL;DR

This review emphasizes the critical role of interface design in halide perovskite devices, highlighting how interface engineering improves performance and stability, and providing a roadmap for future interfacial strategies.

Contribution

It offers a comprehensive overview of interface challenges and opportunities in halide perovskite devices, including physical, chemical, and energetic considerations, and proposes future design principles.

Findings

Interface engineering enhances HaP device stability.

Proper energetic alignment improves charge transport.

Surface properties influence device performance.

Abstract

Design and modification of the interfaces, always a critical issue for semiconductor devices, has become the primary tool to harness the full potential of halide perovskite (HaP)-based ones. In particular the outstanding improvements in HaP solar cell performance and stability can be primarily ascribed to a careful choice of the interfacial layout in the layer stack. In this review we describe the unique challenges and opportunities of these approaches (section A). For this purpose, we first elucidate the basic physical and chemical properties of the exposed HaP thin film and crystal surface (section B). We then lay out the energetic alignment processes to adjacent transport and buffer layers (section C) and finally elaborate on the impact of the interface formation on how well/poor a device functions. Based on those sections we then present a road map for the next steps in interfacial design principles for HaP semiconductors (section D).