Potential well
A potential well is the region surrounding a
Overview
Energy may be released from a potential well if sufficient energy is added to the system such that the local maximum is surmounted. In
The graph of a 2D potential energy function is a potential energy surface that can be imagined as the Earth's surface in a landscape of hills and valleys. Then a potential well would be a valley surrounded on all sides with higher terrain, which thus could be filled with water (e.g., be a lake) without any water flowing away toward another, lower minimum (e.g. sea level).
In the case of gravity, the region around a mass is a gravitational potential well, unless the density of the mass is so low that tidal forces from other masses are greater than the gravity of the body itself.
A potential hill is the opposite of a potential well, and is the region surrounding a
Quantum confinement
Quantum confinement can be observed once the diameter of a material is of the same magnitude as the de Broglie wavelength of the electron wave function.[1] When materials are this small, their electronic and optical properties deviate substantially from those of bulk materials.[2]
A particle behaves as if it were free when the confining dimension is large compared to the wavelength of the particle. During this state, the
Specifically, the effect describes the phenomenon resulting from
Quantum mechanics view
The electronic and optical properties of materials are affected by size and shape. Well-established technical achievements including quantum dots were derived from size manipulation and investigation for their theoretical corroboration on quantum confinement effect.
The following equation shows the relationship between energy level and dimension spacing:
Research results
Classical mechanics view
The Young–Laplace equation can give a background on the investigation of the scale of forces applied to the surface molecules:
Under the assumption of spherical shape and resolving the Young–Laplace equation for the new radii (nm), we estimate the new (GPa). The smaller the radii, the greater the pressure is present. The increase in pressure at the nanoscale results in strong forces toward the interior of the particle. Consequently, the molecular structure of the particle appears to be different from the bulk mode, especially at the surface. These abnormalities at the surface are responsible for changes of inter-atomic interactions and
See also
References
- ISBN 978-1-56677-352-2. Retrieved 19 June 2012.
- ISBN 978-981-02-2002-0. Retrieved 19 June 2012.
- PMID 9983472.
- doi:10.1063/1.445676.
- .
- S2CID 123243150. Archived from the originalon February 18, 2013.
- doi:10.1063/1.482008.
External links
- Buhro WE, Colvin VL (2003). "Semiconductor nanocrystals: Shape matters". Nat Mater. 2 (3): 138–9. S2CID 13634895.
- Semiconductor Fundamental
- Band Theory of Solid
- Quantum dots synthesis
- Biological application