A Monte Carlo code for simulating soft X-ray absorption in pure and two-layer materials

The present paper describes a Monte Carlo code to simulate the cascade of electron-hole pairs and phonons generated when a low-energy X-ray photon is absorbed by a material. The model has been applied to study the response to UV or soft X-ray radiation of diamond and silicon, focused on the case of two-layer material made of diamond film grown on silicon. Typically the statistical distribution of the electron-hole cascade is macroscopically parameterized by the mean energy required to create an electron-hole pair W and the Fano factor F. The results for the pure materials are in agreement with the values present in the literature. Moreover we found an enhancement of the Fano factor and a super-Poissonian behaviour of the statistical distribution of the pairs, typical of correlated systems. (C) 2011 Elsevier B.V. All rights reserved.