The ratio of electron and hole currents in a semi- conductor is 7/4 and the ratio of drift velocities of electrons and holes is 5/4, then ratio of concentrations of electrons and holes will be
The mobility of free electrons is greater than that of free holes because
The typical ionisation energy of a donar in silicon is
The correct relation between ne and nh intrinsic semiconductor at ordinary temperature is in an
When boron is added as an impurity to silicon, the resulting material is
The energy gap of silicon is 1.14eV. The maxi- mum wavelength at which silicon starts energy absorption, will be
(h = 6.62 × 10-34 Js; c = 3 × 108 m/s)
In a p-type semiconductor the acceptor level i situated 60 meV above the valence band. The maximum wavelength of light required to product a hole will be
The relation between number of free electrons (n) in a semiconductor and temperature (T) is given by
Resistivity of a semiconductor depends on
