question_answer

The electrical conductivity of a semiconductor     increases     when electromagnetic radiation of wavelength shorter than 2480 nm, is incident on it. The band gap for the semiconductor is                      [AIEEE 2005]

A) 1.1 eV

B) 2.5 eV

C) 0.5 eV

D) 0.7 eV

Correct Answer: C

Solution :

[c] The band energy gap is