NIEL Calculations for III-V Compound Semiconductors Under Electron or Proton Irradiation

The nonionizing energy loss (NIEL) concept, introduced more than 40 years ago, is still used to characterize the damage generated by different particles and gamma-rays. Its continuing relevance is due to the experimentally established scaling in the creation rate of defects by radiation of different types. NIEL calculations are quite simple, based on classical physics. We thus name them classical NIEL, NIELc. Their calculation depends on an a priori known E-d-displacement threshold energy in monoatomic materials. For the compound semiconductor materials studied here, GaX and InX, where X are the cations N, P, As, Sb, the experimental E-d values vary over a wide range and only approximate values for NIELc can be calculated. Thanks to some recent studies carried out using the molecular dynamic (MD) method, the NIEL values were estimated using atomic scale calculations. Consequently, we can now compare NIELc, with more precise data. These data also include the dynamic behavior of the NIEL, which is related to the annealing of the damage (like Frenkel pair recombination) and the generation of extended crystalline defects. The NIEL calculated using the MD method is referred to in the literature as NIELeff. A detailed comparison between NIEL, and NIELeff as a function of electron and proton energies is made here. It shows that the difference between the two quantities is not large and cannot influence the dependence of NIEL on temperature and different radiation types. Both yield similar results in calculating the effect of displacement damage. As an additional use of NIELc , we analyze its application to estimate the relative tolerance of the different members of the GaX and InX families to radiation defects as a function of particle energies.

Automated summary

This article introduces the concept and calculation method of nonionizing energy loss (NIEL), as well as the importance and relevance of NIEL values research. By comparing classical NIEL (NIELc) and effective NIEL (NIELeff) data, it is shown that they yield similar results in calculating displacement damage effects.