Identification of VH in silicon by EPR

Floatzone grown silicon crystals have been implanted with protons or deuterons. Electron Paramagnetic Resonance (EPR) spectra show the presence of a strongly temperature dependent signal in addition to the well-known S1 signal. The temperature dependent signal displays monoclinic-I symmetry below 65 K and trigonal symmetry above 110 K. The g- and Si-29 hyperfine tensors are characteristic of defects with the unpaired electron confined mostly to a dangling bond orbital in a vacancy-type defect. The signal shows splittings arising from the hyperfine interaction with a single proton. On this basis, and from the close similarity with the familiar VPO signal (the E-center), we conclude that the signal originates from VHO, the neutral charge state of the silicon monovacancy containing a single hydrogen atom.