Electrically detected electron-spin-echo envelope modulation: a highly sensitive technique for resolving complex interface structures.

We show that the electrical detection of electron-spin-echo envelope modulation (ESEEM) is a highly sensitive tool to study interfaces. Taking the Si/SiO2 interface defects in phosphorus-doped crystalline silicon as an example, we find that the main features of the observed echo modulation pattern allow us to develop a microscopic model for the dangling-bond-like P(b0) center by comparison with the results of ab initio calculations. The ESEEM spectrum is found to be far more sensitive to the defect characteristics than the spectrally resolved hyperfine splitting itself.