Q. 14.3     Carbon, silicon and germanium have four valence electrons each. These are characterised by valence and conduction bands separated by energy bandgap respectively equal to (E_{g})_{C},(E_{g})_{Si}  and (E_{g})_{Ge}. Which of the following statements is true?

                (a) (E_{g})_{Si} < (E_{g})_{Ge}< (E_{g})_{C}

                (b) (E_{g})_{C} < (E_{g})_{Ge}> (E_{g})_{Si}

                (c) (E_{g})_{C} > (E_{g})_{Si}> (E_{g})_{Ge}

                (d) (E_{g})_{C} = (E_{g})_{Si}= (E_{g})_{Ge}

Answers (1)
P Pankaj Sanodiya

Since carbon is a non-metal, its energy band gap would be highest and energy band gap of Ge would be least as it is a metalloid.

(E_{g})_{C} > (E_{g})_{Si}> (E_{g})_{Ge}

Hence correct option would be (c)