Carbon, silicon, and germanium have four valence electrons each. These are characterized by valence and conduction bands separated by the energy bandgap respectively equal to (Eg)C, (Eg)Si, and (Eg)Ge. Which of the following statements is true?
1. | (Eg)Si < (Eg)Ge < (Eg)C |
2. | (Eg)C < (Eg)Ge > (Eg)Si |
3. | (Eg)C > (Eg)Si > (Eg)Ge |
4. | (Eg)C = (Eg)Si = (Eg)Ge |
In an intrinsic semiconductor, the energy gap Eg is 1.2eV. Its hole mobility is much smaller than electron mobility and independent of temperature. What is the ratio between conductivity at 600K and that at 300K? Assume that the temperature dependence of intrinsic carrier concentration is given by,
1. \(1.01\times10^6:1\)
2. \(1.09\times10^5:1\)
3. \(1:1\)
4. \(1:2\)