0
Why the band gap increases as the size of nano-particle decreases?
Wiki User
∙ 11y ago
In order to understand quantum confinement, we need to go back to the very basics of quantum mechanics; namely the particle-in-a-box. All we need to worry about is, that the spacings between the energy levels increase as the length of the box decreases. Quantitatively, En = n2h2/8mL2. In the case of semiconductors this simply means that the band gap, starting from the bulk value, increases as the size of the nanocrystal decreases. In bulk solids the energy levels are closely spaced and thus form quasi-continuous bands. Going to the nano-regime the energy level separation increases and discrete energy levels are observed. Calculations on different systems show that quantum confinement effects are observable at sizes below 10 nm for most materials (~20 nm for Pb chalcogenides). Onset of confinement depends on a number of parameters such as the dielectric constant of the semiconductor and effective masses of the charge carriers.
Wiki User
∙ 11y ago
Add your answer:
Earn +20 pts
What will the Elements going across the periodic table from left to right will?
gain electrons more readily and increase in nonmetallic character
Why does atomic size increase as you go from left to right across a period?
atomic size decreases as we go from left to right. as we go from left to right, the number of protons in the nucleus increases, so the effective nuclear charge increases. due to this the electrons are attracted more towards the nucleus and hence, the size decreases.
What is the difference between nanocrystal and nanoparticle?
They are basically the same.However size is the critical issue as larger the size the closer to the properties of the bulk
Why electronegativity increases and decreases alternately in boron family?
firstly boron due to its small size has highest electronegativity in the group.Next Al , has larger size and atomic radii so electronegativity decreases. But in Ga due to the presence of 10 d-electrons , the shielding effect gets reduced. As a result the attraction due to the nuclear charge increases. The same happens with In and Tl. By Ashank
Why acidic character of oxides of group 15 elements decreases down the group?
The ability of the hydride to donate a hydrogen ion can be directly correlated with the decreasing bond strength of the element-hydrogen bond. That is, as the bond strength decreases down the family, the acidity increases. For the same reason, the general chemical reactivity of nonmetal hydrides also increases with increasing atomic number of the nonmetal.
What happens to capillarity as particle size increases?
As particle size in increases, capillarity decreases
When soil particle size decreases capillary action?
increases
What happens to the distance if a machine increases the size of the force?
it decreases
How does a nanoparticle differ from a single ion How does it differ from a piece of a solid?
The size of a nanoparticle is smaller than any one piece of a solid; also an ion is smaller than a nanoparticle.
What happens to the expected value of M as sample size increases?
Decreases
Can the size of the particles that the water can transport increases as the water velocity decreases?
no it does not
As the rate of cooling of igneous rocks increases the size of the crystals that form .?
The size of crystals decreases as the cooling increases. This is called an inverse relationship.
. As the rate of cooling of igneous rocks increases the size of the crystals that form?
The size of crystals decreases as the cooling increases. This is called an inverse relationship.
As the rate of cooling of igneous rocks increases the size of the crystals that form?
The size of crystals decreases as the cooling increases. This is called an inverse relationship.
How does size change in a period and in a group?
Atomic size decreases across a period as the effective nuclear charge increases. Atomic size increases down a group as the energy level (shells) increases.
The influence of genetic drift on allele frequencies increases as?
population size decreases
When cell size increases the surface area to volume ratio does what?
decreases i believe(:
