Table of Contents
What is hole mobility?
The ability of an hole to move through a metal or semiconductor, in the presence of applied electric field is called hole mobility. It is mathematically written as. Vp = µpE.
Do holes have mobility?
Since holes are subjected to the stronger atomic force pulled by the nucleus than the electrons residing in the higher shells or farther shells, holes have a lower mobility. because electron effective mass is smaller than holes therefore mobility of electron is higher than holes.
What is the formula of mobility?
The dimensions of force and and charge = [M1 L1 T-2] and [I1 T1] respectively. Or, M = [M0 L1 T-1] × [M1 L1 T-3 I-1]-1 = [M-1 L0 T2 I1]. Therefore, mobility is dimensionally represented as [M-1 L0 T2 I1].
What is mobility of electrons in silicon?
In silicon (Si) the electron mobility is of the order of 1,000, in germanium around 4,000, and in gallium arsenide up to 10,000 cm2/ (V⋅s). Hole mobilities are generally lower and range from around 100 cm2/ (V⋅s) in gallium arsenide, to 450 in silicon, and 2,000 in germanium.
Which has greater mobility electrons or holes?
Electron has higher mobility than hole in a semiconductor.
Why do holes move slower than electrons?
Holes generally move more slowly than electrons, however, because they function within the tightly bound valence band rather than the conduction band. Ordinary temperatures are not high enough to excite many electrons into the conduction band.
What is mobility of semiconductor?
Mobility in a semiconductor is defined as how speedily charge carriers like electrons move in a semiconductor.
What is the mobility of holes and electrons in intrinsic semiconductor?
Mobilities of electrons and holes in a sample of intrinsic germanium at room temperature are 0.36m2V−1s−1 and 0.17m2V−1s−1.
Why is hole mobility less?
The conduction band electron effective mass is usually smaller than the valence band hole effective mass. This is one of the reasons that in a semiconductor the electron mobility is usually larger than the hole mobility.
Which has higher mobility electron or hole?
What is meant by mobility in semiconductor?
Why the mobility of holes is smaller than the electrons in Si semiconductors?
Why the mobility of holes is less than conduction electrons?
As valence band has stronger nucleic force, hole experiences difficulty in movement, unlike conduction electron which is free to move. So, the mobility of hole is less when compared to that of conduction electron.
Why is electron mobility faster than hole?
The conduction band is at a higher energy level than the valence band and that means that things move faster. More interestingly, for an electron to move from the conduction band to the valence band (and fill the hole) it must lose some energy.
What is the mobility of electrons and holes?
Electron and hole mobility are special cases of electrical mobility of charged particles in a fluid under an applied electric field. Electron mobility is almost always specified in units of cm2/(V⋅s). This is different from the SI unit of mobility, m2/(V⋅s). They are related by 1 m2/(V⋅s) = 104 cm2/(V⋅s).
Why mobility of holes is less than electrons in intrinsic semiconductors?
Intrinsic semiconductors are made of pure elements. The mobility of electrons and holes depends on their effective masses. The effective mass of electrons is less than that of holes hence electrons have higher mobility than holes.
Which have higher mobility electron or hole?
Why mobility of electrons is more than holes?
The mobility of free electron is greater than that of free holes because they require low energy to continue their motion.