Which one of the following semi-conductors possesses the highest value

Which one of the following semi-conductors possesses the highest value of band gap Eg?

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GaAs

PbS

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This question was previously asked in

UPSC Geoscientist – 2023

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The band gap (Eg) values for the given semiconductors are approximately:
Si (Silicon): ~1.1 eV (indirect band gap)
Ge (Germanium): ~0.67 eV (indirect band gap)
GaAs (Gallium Arsenide): ~1.42 eV (direct band gap)
PbS (Lead Sulfide): ~0.37 eV (direct band gap)
Comparing these values, GaAs has the highest band gap among the options.

The band gap is the energy difference between the top of the valence band and the bottom of the conduction band. This value is a key characteristic of semiconductor materials.

Semiconductors are classified by their band gap, which can be direct or indirect. A larger band gap generally means the material is less conductive. Materials with larger band gaps (e.g., GaN, SiC) are used in high-power, high-temperature, and high-frequency applications, as well as in blue/UV light emitters.

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