Two-dimensional perovskite niobate materials for multifunctional photodetectors

Over the past decade, the material system of two-dimensional perovskite niobates has undergone a remarkable and rapid evolution, marked by significant expansion and groundbreaking innovation. This evolution has propelled substantial progress across multiple key areas, including material synthesis techniques, structural modulation strategies, and in-depth performance exploration. In the realm of material synthesis, a wide variety of techniques have been explored. These approaches have facilitated the fabrication of two-dimensional perovskite niobates with precise control over parameters such as layer thickness, lateral dimensions, and defect densities. Structural modulation has been another focal point, with scientists exploring ways to engineer crystal structures at the atomic scale. By introducing various dopants or altering the stoichiometry of the materials, they have been able to fine-tune the electronic band structures and crystal symmetries, which in turn significantly impact the physical and chemical properties of the materials. The exceptional properties of two-dimensional niobate perovskites render them highly promising for multifunctional optoelectronic detection applications. Their ultrahigh specific surface area not only provides an extensive interface for interactions with external stimuli but also enhances the adsorption and reaction capabilities, which are crucial for sensitive detection. The excellent flexibility and transparency make them ideal candidates for the fabrication of flexible and transparent optoelectronic devices, opening up new avenues for wearable electronics and transparent display-integrated sensing systems. Moreover, their high chemical stability ensures long-term operational reliability, reducing the risk of material degradation under harsh environmental conditions. The unique physical characteristics, such as dielectric, ferroelectric, and semiconducting behaviors, offer a rich palette of functionalities that can be harnessed for diverse detection mechanisms, including photodetection, sensing of chemical and biological molecules, and signal conversion. Despite the continuous emergence of numerous experimental studies and innovative device designs, the field of two-dimensional perovskite niobates for optoelectronic detection lacks comprehensive and systematic reviews. As a result, the existing research findings are scattered, making it difficult for researchers to gain a holistic understanding of the current state-of-the-art and identify potential research directions. To address this gap, this review aims to comprehensively consolidate the latest research advances in two-dimensional perovskite niobates for optoelectronic detection. It conducts a critical and in-depth review of their application efficacy in various optoelectronic device architectures. For single-material-based prototype devices, the review analyzes how the intrinsic properties of two-dimensional perovskite niobates contribute to device performance. In composite material systems designed for performance optimization, it explores the synergistic effects between different components and how they enhance the overall detection capabilities. Regarding photonic synaptic devices that mimic neuromorphic computing, the review delves into the mechanisms of information processing and storage, as well as the potential for developing intelligent sensing systems. Additionally, for optoelectronic-dielectric bifunctional integrated devices, it discusses the integration strategies and the resulting multifunctionalities. Furthermore, this review meticulously analyzes the core challenges faced by the material system of two-dimensional perovskite niobates in optoelectronic detection applications. These challenges include issues related to material scalability, device stability under long-term operation, and the development of efficient interface engineering techniques. By thoroughly understanding these challenges, the review also provides a forward-looking perspective on future development directions in the field. It explores potential solutions to overcome the existing limitations and outlines emerging research trends that could drive the further development of high-performance optoelectronic devices based on two-dimensional niobate perovskites. The ultimate goal of this review is to offer valuable insights and guidance for researchers engaged in the design and development of advanced optoelectronic devices, thereby facilitating the realization of their full potential in a wide range of applications.