p+-Si-n-CdF2 heterojunctions

Boron diffusion and the vapor-phase deposition of silicon layers are used to prepare ultrashallow p+-n junctions and p+-Si-n-CdF2 heterostructures on an n-CdF2 crystal surface. Forward portions of the I–V characteristics of the p+-n junctions and p+-Si-n-CdF2 heterojunctions reveal the CdF2 band gap (7.8 eV), as well as allow the identification of the valence-band structure of cadmium fluoride crystals. Under conditions in which forward bias is applied to the p+-Si-n-CdF2 heterojunctions, electroluminescence spectra are measured for the first time in the visible spectral region.