New Paramagnetic Center In Amorphous Silicon Doped With Rare-earth Elements

Abstract

A new paramagnetic center associated with rare earths (RE) (La, Ce, Pr, Nd, Gd, Er, and Lu) in amorphous silicon is reported. It is shown that RE impurities are incorporated in a-Si and that the density of paramagnetic dangling bonds decreases as a consequence of the presence of these impurities. An interpretation in terms of RE 6s orbitals and crystal-field-split 5d orbital hybridization suggests that the RE behaves as an acceptor impurity with an associated hole in the a-Si valence-band tail, which is responsible for the observed resonance at a g value of 2.100.01. © 1989 The American Physical Society.