Thapa Dev Kumar, Biswas Soumava
Department of Chemistry, Dr. Vishwanath Karad MIT World Peace University, Survey No. 124, Paud Rd, Kothrud, Pune, Maharashtra 411038, India.
Nanoscale. 2025 Mar 28;17(13):7651-7672. doi: 10.1039/d5nr00091b.
A single photon source (SPS) is a device designed to emit photons, one at a time, enabling precise control over quantum states, unlike classical light sources that produce interfering streams. This capability is crucial for secure communication protocols such as quantum key distribution and for quantum networks, where single photons act as carriers of quantum information. Recent advancements have led to various SPS technologies, including quantum dots (QDs), atom-like emitters, and color centers in diamonds. Among these, QDs, semiconductor nanocrystals, have gained significant attention due to their unique optical and electronic properties derived from quantum confinement effects. They offer size-dependent tuning of emission wavelengths, high photoluminescence efficiency, and discrete energy levels, making them ideal for single photon applications while exhibiting scalability and low background noise. This review provides a comprehensive overview of recent advancements in quantum dot-based SPSs operating at room temperature, highlighting their optical properties, essential performance metrics, and the latest developments in single photon generation. It also discusses strategies to mitigate blinking and improve photon statistics through techniques such as plasmonic nanocavity and ligand exchange. The review concludes by outlining the challenges faced in the field and discussing potential solutions.
单光子源（SPS）是一种设计用于一次发射一个光子的装置，与产生干涉光束的经典光源不同，它能够对量子态进行精确控制。这种能力对于诸如量子密钥分发等安全通信协议以及量子网络至关重要，在量子网络中，单光子充当量子信息的载体。最近的进展催生了各种单光子源技术，包括量子点（QD）、类原子发射器和金刚石中的色心。其中，量子点作为半导体纳米晶体，因其源自量子限制效应的独特光学和电子特性而备受关注。它们提供发射波长的尺寸依赖性调谐、高光致发光效率和离散能级，使其成为单光子应用的理想选择，同时具有可扩展性和低背景噪声。本综述全面概述了室温下基于量子点的单光子源的最新进展，重点介绍了它们的光学特性、关键性能指标以及单光子产生的最新发展。它还讨论了通过等离激元纳米腔和配体交换等技术减轻闪烁并改善光子统计的策略。综述最后概述了该领域面临的挑战并讨论了潜在的解决方案。
