Table of Contents
Why the band gap of silicon is greater than germanium?
The electrons in the silicon atoms are more tightly bound to the nucleus than the electrons of the germanium atom due to its small size. This is the reason why the band gap of silicon is more than that of germanium.
Why does silicon have a band gap?
Silicon and germanium have significantly weaker bonding between their atoms. This results in a smaller band gap. At room temperature, some of the electrons have enough energy to move into the conduction bands.
Why silicon is better semiconductor than germanium?
Why is silicon usually preferred to germanium in the manufacture of semiconductor devices? Silicon is abundant on the earth’s surface and therefore cheaper than germanium. The PIV (Peak Inverse Voltage) rating of silicon is much higher than germanium and therefore can withstand much higher temperatures than germanium.
When comparing the energy gap of germanium and silicon atoms a silicon atom’s energy gap is?
Therefore, Germanium and Silicon have an energy gap of 0.75 and 1.12 eV respectively, are considered most suitable for semiconductor materials.
What is the largest band gap?
So, one good semiconductor material for the future is C (diamond). It has the largest thermal conductivity and band gap of any of the materials from Table 10.2. Diamond also has the largest electron mobility of any material from Table 10.2 with a band gap larger than Si.
Why do band gap exist?
When two or more atoms join together to form a molecule, their atomic orbitals overlap. The inner electron orbitals do not overlap to a significant degree, so their bands are very narrow. Band gaps are essentially leftover ranges of energy not covered by any band, a result of the finite widths of the energy bands.
Why germanium is not used in SCR?
Thyristor is not made using germanium, because. its current handling capacity is less than silicon. it is a stable semiconductor. it has high leakage current.
What is energy gap of SI?
The energy required for electrons and holes to transition from the valence band to the conduction band is called a band gap. Si (Silicon) has a band gap of 1.12 eV (electron volt).
What is the forbidden energy gap?
Forbidden energy gap, also known as band gap refers to the energy difference (eV) between the top of valence band and the bottom of the conduction band in materials. Current flowing through the materials is due to the electron transfer from the valence band to the conduction band.
What are the disadvantages of germanium?
Germanium has disadvantages in addition to the need for cooling: energy resolution is sensitive to radiation damage (a feature common to all semiconductor diode-type detectors) and efficiency is low for higher energy gamma rays.
What is the energy gap between silicon and germanium?
It generally refers to the energy difference (in electron volts) between the top of the valence band and the bottom of the conduction band in insulators and semiconductors. The energy band gaps of silicon and germanium are 1.1eV and 0.7eV respectively.
Why does Si have more band gap than Ge?
At room temperature Si crystal has almost no free electrons as compared to Ge crystal, this is because Si has more band gap than Ge. Band gap is the energy difference between the bottom of the conduction band and the top of the valence band, it can also be defined as that part of the energy band where no electrons exist.
Why is silicon band gap energy more than 3SP?
So energy gap is more in that case. If one looks at the band structure from a tight-binding point of view, the overlap between the germanium 4sp orbitals on neighbouring sites is larger than for silicon 3sp. So bandwidts are increased, leaving less room for gaps.
Which is a better conductor germanium or silicone?
Germanium is a better conductor (although it is a semiconductor), whereas Silicone is a better semiconductor. Both Ge and Si are tetravalent elements i.e. 4 valence electrons in the outer most orbit. Ge was widely used in the earlier days of semiconductors, but these days it is rarely used in new designs.