Exponential depletion of neutral dangling bonds density (D ~0) by rare-earth doping in amorphous Si films (Conference Paper)

摘要

In this work we study the effect reduction in the density of dangling bond species D ~0 states in rare-earth (RE) doped a-Si films as a function concentration for different RE-specimens. The films a-Si _(1-x)RE _x, RE=Y ~3, Gd ~3, Er ~3, Lu ~3) were prepared by co-sputtering and investigated by electron spin resonance (ESR) and Raman scattering experiments. According to our data the RE-doping reduces the ESR signal intensity of the D ~0 states with an exponential dependence on the rare-concentration. Furthermore, the reduction produced by the magnetic rare-earths Gd ~3 and Er ~3 is remarkably greater than that caused by Y ~3 and Lu ~3, which led us to suggest an exchange-like coupling between the spin of the magnetic REs ~3 and the spin of silicon neutral dangling bonds.