Impact excitation of carriers in diamond under extremely high electric fields

Impact ionization process in diamond under extremely high electric fields ( EFs) has been investigated. The impact-ionization rate was calculated theor etically from Fermi's golden rule using the full band structure. It is foun d from Monte Carlo simulations that the impact ionization of carriers occur s at high EFs above 1 x 10(6) V/cm. The threshold EF for ionization is smal ler for hole than for electron. Current(I)-voltage(V) characteristics measu red for p-i-p diamond stacking structures revealed that I is approximately proportional to V-2 with substantial electroluminescence at EFs higher than 5 x 10(6) V/cm, being in good agreement with the theoretically predicted v alues.