Quantum dots are particles of semiconductor material with the size so small that the electron energies that can exist within them are limited. These energy levels, defined by the size of quantum dots, in turn define the bandgaps. The dots can be grown to any needed size, allowing them to be tuned across a wide variety of bandgaps without changing the underlying material or construction techniques
1. Introduce
◎ 하드디스크 드라이브와 다른 첨단 기술의
저장장치를 제조
◎ 1980년 설립
◎ 직원 : 전세계적으로 약 5,900명
◎ 영업지역 : 북미, 아시아 태평양, 유럽
◎ 매출액 : 2003 회계연도 (03.3.31마감)
8억 7100만 달러
2. Quantum사의 문제점 및 Business Challenges
▷ 수작업 재고파악, 많은
Free(wannier-mott)
Radius >> a(exciton Bohr radius)
Small binding energy :~ 0.01 eV
Delocalized states
Move freely through crystal
(semiconductors)
Tighthly-bound(Frenkel)
Radius ~ a(exciton Bohr radius)
large binding energy : 0.1 -1.0 eV
localized on one lattice site
Moving by hopping
(insulators and molecules)
Eadd = △E + Ec
Ec = e2/C
C = 2πεεod
(depend on geometr
Potential bio-accumulation of nanoscale particles.
Accumulation of a substance within a species can occur due to lack of degradationor excretion
Many nanoparticles are not biodegradable.
If nanoparticles enter organisms low in the food web, they may be expected to accumulate in organisms higher in the food web.
Very little is understood about possible health
effects of nanoparti