Energy Band Theory and Electrical Properties of Matter

Elemental semiconductor cannot be used to make visible LEDs.

What are elemental semiconductors?

Valence band is-

Describe the theory of valence band?

Conductivity is an object's ability to transmit current.

The reverse of conductivity is-

What is the SI unit of conductivity for an object?

Write a distinguishing features between conductors, semiconductors and insulators on the basis of energy gap and Conductivity.

Which of the following arrangements is correct on the basis of conductivity of materials?

What is Conduction band?

In a semiconductor at room temperature, conduction band is partially filled.

The conduction band is completely empty in _____.

The energy band gap of gallium arsenide phosphate is $1.98 e\mathrm{V}$. Calculate the wavelength of electromagnetic radiation emitted (in Angstrom), when electrons and holes combine in this alloy semiconductor directly. (Take Planck's constant $\left(h\right)=6.62\times {10}^{-34 }\mathrm{J} \mathrm{s}$)

If the energy of a photon of sodium light $(\mathrm{\lambda }=589 \mathrm{n}\mathrm{m})$ is equal to the bandgap of a semiconductor, calculate the minimum energy required to create hole-electron pair. Take, $h=6.6\times {10}^{-34} \mathrm{J} \mathrm{s}, c=3\times {10}^8 \mathrm{m} {\mathrm{s}}^{-1}$.

Describe the conduction band and valence band in insulators.

When the electrical conductivity of a semi-conductor is due to the breaking of its covalent bonds, then the semiconductor is said to be

Si and Cu are cooled to a temperature of $300 \mathrm{K}$, then conductivity,

The conductivity of a semiconductor increases with increase in temperature because the number density of free current carriers increases.

In a conductor, the energy gap between conduction bands and valence bands is

While comparing a compound semiconductor with an elemental semiconductor, which of the following statement is not correct?