Nondegrading photoluminescence in porous silicon by deuterium plasma treatment

Porous silicon (PS) with nondegrading photoluminescence (PL) was obtained by deuterium plasma treatment. We demonstrate that the structural stability of deuterated PS is much better than that of normal PS. The secondary-ion-mass spectrometry and infrared-absorption spectra reveal the formation of Si-D bonds on the surface of PS. The Raman spectra show the evidence of the coupling between the Si-D wagging mode and transverse Si-Si optical phonon. This coupling leads to the relaxation of the accumulated energy and hence the reduction of the bond breaking. All our results indicate that the possible mechanism of the PL stability in deuterated PS can be attributed to the existence of Si-D bonds on the surface of PS. © 2002 The American Physical Society.