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bandgap has an importance role for conduction.if bandgap is max,the conduction of electron is min. and vice-versa.hence we can say that the bandgap desides the conductivity of any material(may be metal or nonmetal)
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Why indirect band gap material is used for manufacturing LED's?
Optical sources like LEDs use direct band gap so that conduction band electorn can recombine directly with a hole in valence band .
What is true of semiconductors?
Full question is: What is true of semiconductors A have a larger band hap than insulators B Doping a semiconductor makes it less conductive C Electrons conduct well if they are in a filled valence band D Conduction band is higher in energy than the valence band E Holes refer to empty atomic sites in a solid crystal Semiconductors do not conduct current as well as conductors.
Why N Type Semiconductors are preferred over P Type Semiconductors?
since n type semiconductors have high mobility for electrons, they are preffered over ptype
What are p type semiconductors?
P type semiconductors have been doped with trivalent elements, causing them to conduct via "hole" flow. N type semiconductors have been doped with pentavalent elements, causing them to conduct via electron flow.
What is the meaning of semiconductors?
Oversimplifying it significantly "not quite conductors". These are materials whose ability to conduct electricity is between conductors and insulators but can be very precisely controlled by doping with other elements as impurities, allowing the construction of electronic devices that can: control the direction of current flow, amplify signals, act as switches, perform boolean logic functions, etc. These materials can be classed as elemental semiconductors, binary semiconductors, other semiconductors. The elemental semiconductors are elements with 4 valence electrons that are not metals (e.g. silicon, germanium), the binary semiconductors are "alloys" of two elements: one with 3 valence electrons and the other with 5 valence electrons (e.g. gallium arsenide, indium phosphide), other semiconductors can be elements (e.g. selenium) compounds (e.g. galena, copper oxide) or complex "alloys" of several elements (e.g. gallium arsenide phosphide, aluminum gallium indium phosphide). The term semiconductors is also used to refer to the electronic devices mades of these materials.
Why do we mostly use indirect semiconductors?
The indirect band gap semiconductors like silicon and germanium are mostly used because they are elemental, plentiful, and easier to process than the direct band gap semiconductors which are alloys or compounds.
What are the Characteristics of Direct and indirect band gap semiconductors?
Direct band semconductors are mostly for LEDs. Indirect band semiconductors like Si and Ge are conventional diodes.
What is the highest band gap value for semiconductors?
Fairly certain Beryllium Oxide is an extrinsic semiconductor with band gap 10.6 eV. Otherwise the answer is Boron Nitride (6.36 eV)
Titanium dioxide is direct band gap or indirect band gap material?
Yes it is. Most Sn (tin) materials as semiconductors are direct band gap materials. Silicon on the other hand is an indirect band gap material.
What has the author R Dornhaus written?
R. Dornhaus has written: 'Narrow-gap semiconductors' -- subject(s): Narrow gap semiconductors
What is transparent electronics?
The term transparent electronics refers to devices that has wide band gap semiconductors. The devices also contain active oxides in active components.
What is burstein-moss shift?
The shift in the optical band gap of any material, usually semiconductors, due to doping effect is known as Bursteing-Moss shift.
Do semiconductor material have a very high resistance at room temperature?
No. As temperature increases, resistance of semiconductors decrease. This is because semiconductors have a small energy gap between their valence band and conduction band (in the order of 1 eV). Electrons must exist in the conduction band in order for the material to conduct but electrons exist in the valence band naturally. The electrons gain thermal energy for surroundings and jumps the energy gap from valence band to conduction band and hence, the SC material more readily conducts. As temperature increases, electrons can gain more thermal energy, more electrons can enter the conduction band and hence, resistance decreases.
When was The Gap Band created?
The Gap Band was created in 1967.
What makes silicon a semiconductor?
Elements have two bands. One is Valence band and other is Conduction band. Valence band contains electrons whereas the conduction band is empty. The energy gap between them is called the forbidden gap. In case of metals, this gap is very small or the bands overlap. Therefore, the electrons are able to jump from the valence band to the conduction band and hence metal are able to conduct electricity and they are generally conductors. In case of Non-Metals, the energy gap is very large and hence hence electrons are not able to move from valence band to conduction band. Hence they are insulators. But in case of elements like Silicon, Germanium this gap is between Metals and Non-Metals, hence few electrons are able to move from valence band to conduction band. Therefore they have some conductivity but it is low and hence they are called semiconductors.
Why in intrinsic semiconductors do you need to apply very high potential to transfer electrons from the valence band to the conduction band?
Semiconductors, in the absence of applied electric fields, act a lot like insulators. In these materials, the conduction band and the valence band do not overlap. That's why they insulate. And that's why you have to apply some serious voltage to them to shove the valence electrons across the gap between the valence and conduction bands of these semiconductor materials. Remember that in insulators, there is a "band gap" between the lowest Fermi energy level necessary to support conduction and the highest Fermi energy level of the valence electrons. Same with the semi's. In metals, the conduction band overlaps the valence band Fermi energy levels. Zap! Conductivity.
Are free electron in valence band or conduction band?
In semiconductors free electrons are in conduction bands.
