Dopant-Induced Electric Fields and Their Influence on the Band-Edge Absorption of GaN

Dopant-induced local electric fields and their influence on the band-edge absorption of GaN are theoretically examined. For dopant-induced electric field distribution, it is derived with Bayes’ rule. For the average electric field strength, it is revealed to be quite strong, i.e., in an order of 104 V/cm in GaN with a fairly low dopant density. On the basis of the Franz–Keldysh mechanism, influence of the dopant-induced electric fields on the band-edge absorption coefficient of GaN is then investigated. Without any adjustable parameters, absorption coefficients of GaN are computed and in good agreement with the available experimental values.