Quantum dots (QDs), as a novel nanomaterial, possess exceptional optical properties. With the progression of research, quantum dots have played a significant role in various fields such as optoelectronic devices, biological imaging, solar cells, and display technologies. Indium phosphide (InP) quantum dots have garnered widespread attention as a potential alternative to cadmium-based quantum dots due to their low toxicity and high efficiency. The emission spectrum of InP quantum dots covers the entire visible light region, and their photoluminescence quantum yield (PLQY) and optoelectronic performance are comparable to those of cadmium-based quantum dots. However, there are notable differences between InP quantum dots and cadmium-based quantum dots in terms of precursor materials, growth mechanisms, and core-shell lattice matching. These differences somewhat affect their optical properties, thereby limiting their application in display devices. This article reviews the current development status of InP quantum dot materials and their quantum dot light-emitting diodes (QLEDs). It begins by introducing the fundamental characteristics of InP quantum dots and discusses the optimization and improvement of their optical properties from the perspectives of enhancing color purity and eliminating defect states. Subsequently, it explores the impact of quantum dot structure and device architecture (charge transport layers and interface engineering) on the performance of InP QLEDs, along with the research progress and achievements of InP QLEDs in related applications. Finally, the article outlines the development of the InP quantum dot system and the main challenges it faces, proposing expectations for the future development of the InP quantum dot system, aiming to provide insights and directions for further research and application of InP quantum dot systems.
Significance This review systematically summarizes the latest advancements in indium phosphide (InP) quantum dots (QDs), spanning from synthesis optimization to applications in quantum dot light-emitting diodes (QLEDs). Through precursor regulation, core-shell structure design, and interface engineering, we demonstrate effective strategies for enhancing the luminescent efficiency and color purity of QDs, thereby providing crucial theoretical support for developing high-performance cadmium-free QLEDs. The article reports that current red/green-emitting devices can approach the performance levels of their cadmium-based counterparts, while also revealing the key limiting factors affecting the efficiency of blue-emitting devices. These findings offer critical insights for overcoming technical bottlenecks in full-color display systems. This work holds significant implications for advancing display technologies with wide color gamut and extended operational stability, addressing both fundamental challenges and practical requirements in next-generation.
Progress This review provides a systematic and comprehensive overview of InP quantum dot-based QLEDs, covering aspects from quantum dot materials to device structures. The review is divided into two main sections, focusing on the optimization of InP quantum dot materials and the enhancement of QLED device performance, respectively. The first section centers on the synthesis and performance optimization of InP quantum dot materials. It begins with a discussion on improving the luminescence color purity of InP quantum dots, detailing the selection strategies for reaction precursors (such as indium and phosphorus sources) during the synthesis process. This highlights the critical role of precursor selection in producing high-quality InP quantum dots. Additionally, the reaction mechanisms of InP quantum dot synthesis are explored. The separation of MSCs (Molecular Cluster Species) provides new insights for further investigating the synthesis mechanisms of InP quantum dots. Subsequently, a series of effective methods to enhance the optical performance of InP quantum dots are elaborated, including shell growth and surface ligand modification. These methods not only significantly improve the quantum yield of InP quantum dots but also enhance their stability and color purity, laying a solid foundation for their application in QLEDs. The second section focuses on InP QLEDs, summarizing the factors influencing their electroluminescence performance, including quantum dot emission layer materials, device structure optimization, and QLED interface modifications. By improving the quantum dot emission layer materials and optimizing device structures (such as introducing efficient electron transport layers and hole transport layers), the performance of InP QLEDs has been significantly enhanced. Furthermore, interface modifications (such as interface passivation and energy level alignment) have proven to be crucial for improving device efficiency and stability. This section also systematically reviews recent advancements in red, green, and blue InP QLEDs, demonstrating their great potential in display technologies. Finally, the review briefly summarizes the current progress of InP QLEDs and discusses the challenges faced by the InP quantum dot system, along with prospects for its future development.
Conclusions and Prospects This paper provides a concise overview of the current research status of InP quantum dots and InP QLEDs. In recent years, significant advancements in the synthesis techniques of InP quantum dots have led to remarkable improvements in their optical properties, which have greatly propelled the development of InP QLEDs. Breakthroughs have been achieved in red, green, and blue InP QLEDs. Additionally, the paper delves into the major challenges facing the InP quantum dot system and offers insights into the future development directions of InP quantum dots and QLEDs to provide inspiration and guidance for further research and applications of the InP quantum dot system.