Figure 2
From: Magnetic field dependence of singlet oxygen generation by nanoporous silicon
Photoluminescence of porous silicon containing a high concentration of molecular oxygen. Photoluminescence (PL) spectra of a porous silicon sample exposed to a larger quantity of oxygen gas than in Figure1 are shown for magnetic fields of 0 to 6 T. As in Figure1, the sample was held in superfluid helium at 1.5 K, and the PL was excited with 450-nm (2.76 eV) continuous wave excitation. The vertical dashed line again indicates the threshold energy for energy transfer, at which the quenching of the PL is particularly efficient. Other structures arise from energy transfer processes in which phonons participate.