This review article by Debasis Bera, Lei Qian, Teng-Kuan Tseng, and Paul H. Holloway from the University of Florida provides a comprehensive overview of quantum dots (QDs), focusing on their structure, properties, and multimodal applications. QDs are semiconductor nanocrystals with particle sizes in the nanometer range, which exhibit unique optical and electronic properties due to quantum confinement effects. The article discusses the processing-structure-properties-performance relationships for compound semiconducting QDs, including various synthesis methods and their resulting properties. Key topics covered include: 1. **Structure of Quantum Dots**: The core structure, surface structure, and phase transitions of QDs are explored, highlighting how these factors influence their optical and electronic properties. 2. **Properties**: The article delves into quantum confinement effects, band-gap tuning, and luminescence properties, such as radiative relaxation and non-radiative processes. 3. **Synthesis Processes**: Both top-down and bottom-up approaches to synthesizing QDs are discussed, including wet-chemical and vapor-phase methods. 4. **Applications**: The multimodal applications of QDs in electroluminescence devices, solar cells, and biological imaging are reviewed, emphasizing their potential in optoelectronics and biotechnology. The review also addresses the challenges and advancements in QD research, such as surface passivation techniques, multi-shell structures, and the development of more stable and efficient QDs. Overall, the article serves as a valuable resource for researchers and students interested in the latest developments and applications of quantum dots.This review article by Debasis Bera, Lei Qian, Teng-Kuan Tseng, and Paul H. Holloway from the University of Florida provides a comprehensive overview of quantum dots (QDs), focusing on their structure, properties, and multimodal applications. QDs are semiconductor nanocrystals with particle sizes in the nanometer range, which exhibit unique optical and electronic properties due to quantum confinement effects. The article discusses the processing-structure-properties-performance relationships for compound semiconducting QDs, including various synthesis methods and their resulting properties. Key topics covered include: 1. **Structure of Quantum Dots**: The core structure, surface structure, and phase transitions of QDs are explored, highlighting how these factors influence their optical and electronic properties. 2. **Properties**: The article delves into quantum confinement effects, band-gap tuning, and luminescence properties, such as radiative relaxation and non-radiative processes. 3. **Synthesis Processes**: Both top-down and bottom-up approaches to synthesizing QDs are discussed, including wet-chemical and vapor-phase methods. 4. **Applications**: The multimodal applications of QDs in electroluminescence devices, solar cells, and biological imaging are reviewed, emphasizing their potential in optoelectronics and biotechnology. The review also addresses the challenges and advancements in QD research, such as surface passivation techniques, multi-shell structures, and the development of more stable and efficient QDs. Overall, the article serves as a valuable resource for researchers and students interested in the latest developments and applications of quantum dots.