An in-depth study linking the infrared spectroscopy and photoluminescence of porous silicon during ambient hydrogen peroxide oxidation

We carefully tailored a porous silicon (pSi) surface by oxidation with hydrogen peroxide (H₂O₂) to determine the time-dependent changes in nanocrystallite surface chemistries (e.g., Si-O-Si, SiHx [x=1, 2], OySiH [y=2, 3], and SiOH/H₂O) and their influence on the pSi photoluminescence (PL). The relationship between infrared band amplitudes and PL intensity were evaluated underH₂O₂ andO₃ (previously studied) oxidation. The pSi surface composition under O₃ and H₂O₂ oxidation conditions tended to, save the OySiH(y=2, 3) species, approach similar values at the longest oxidation times studied, but they took very different paths in reaching these end points. Furthermore, the pSi surface compositions that exhibit maximum/minimum PL under each oxidant are very different.