Study of non-radiative silicon deexcitation in an oxygen atmosphere using the differential measurement of the excited state lifetimes

Having developed a new method of differential lifetime measurement using atomic ionoluminescence as an excitation process, we applied this method to a monocrystaline silicon sample in an oxygen atmosphere of variable pressure. We found decreased values of the experimental lifetimes concerning levels 4s ³ P ⁰ and 4s ¹ P ⁰, which are more marked when the oxygen pressure increases. This tends then towards a saturation of the observed phenomenon. We propose, in agreement with other authors, an explanation which is based on the existence of non-radiative deexcitations. We present also a mathematical model for calculating this transition effect on the lifetime measurements. We consider that it is possible to take advantage of this experimental lifetime variation to determine a parameter of the model which characterises the non-radiative deexcitations. This measuring method appears to be a simple and original procedure for the study of certain nonradiative transitions.