Dynamic photoluminescence change of porous Si upon exposure to thermoelectrons/D atoms and D2O

In situ photoluminescence (PL) and transmission IR spectral measurements ha ve been carried out for porous Si (PS) after exposure to thermoelectrons an d subsequent exposure to D atoms or D2O. Upon exposure to thermoelectrons t he PL band (765 nm) of the PS almost diminished accompanied by the intensit y reduction of the IR bands due to Si-H-x (x = 1-3) species. A subsequent D atom exposure resulted in a recovery of the PL band with the formation of Si-D-x bonds. In contrast, D2O exposure gave rise to a new PL band at 650 n m in addition to a 745 nm band accompanied by the emergence of IR bands due to Si-OD and Si-D bonds: the integrated PL intensity after the D2O exposur e is 1.2 times larger than the PL intensity of the as-anodized PS. These re sults suggest that the PL of the PS contains an important contribution from the surface Si-O bonds. (C) 2000 American Institute of Physics. [S0003-695 1(00)04114-0].