chemistry
posted by WIlliam .
Gallium Arsenide

The charge carrier density of GaAs at 31o C is 2.25x106 cm3.
What is the charge carrier density (in cm3) at 175oC?
(The bandgap of GaAs is 1.42 eV. )
I am trying with arrhenius relationship but get confused over "charge carrier density"

charge carrier density here means how many electrons per cm^3
will go into conductivity band
For temp1, 31C > 304.2K
2.25*10^6 = exp(  2.275*10^19 / (1.381*10^23 * 304.2))
For temp2, 175C > 448.2K
x = exp(  2.275*10^19 / (1.381*10^23 * 448.2))
put this into wolfram alpha
(2.25*10^6/x) = exp(  2.275*10^19 / (1.381*10^23 * 304.2)) / exp(  2.275*10^19 / (1.381*10^23 * 448.2))
=> 8.09*10^13