Colloidally synthesized luminescent nanocrystals (NCs) have attracted tremendous attention due to their unique nanoscale optical and electronic properties. The emission properties of these NCs can be precisely tuned by controlling their size, shape, and composition as well as by introducing appropriate dopant impurities. Nowadays, these NCs are actively utilized for various applications such as optoelectronic devices including light emitting diodes (LEDs), lasers, and solar cells, and bio-medical applications such as imaging agents and bio-sensors. In this review, we classify luminescent nanomaterials into quantum dots (QDs), upconversion nanoparticles (UCNPs), and perovskite NCs and present their intrinsic emission mechanism. Furthermore, the recently emerging issues of efficiency, toxicity, and durability in these materials are discussed for better understanding of industry demands. As well, the future outlook will be offered for researchers to guide the direction of future research.

Abstract
 1. 서 론
 2. 양자점
  2.1. 양자점 발광 원리
  2.2. 양자점 소재군 및 이의 응용
 3. 업컨버젼 나노입자(UCNPs)
  3.1. 업컨버젼 메커니즘
  3.2. 업컨버젼 나노입자 소재 및 응용
 4. 페로브스카이트(Perovskite)
  4.1. 페로브스카이트 소재군 및 응용
 5. 맺음말
 References

• 정혜원(울산과학기술원(UNIST) 신소재공학부) | Hyewon Jeong
• 손재성(울산과학기술원(UNIST) 신소재공학부) | Jae Sung Son Corresponding Author