  Nanoscale silicon p(+)-n junctions with very high concentration of boron, 5
10^21 cm-3, are found to demonstrate interesting optical properties. Emission
band dominated in near-infrared electroluminescence (EL) spectra possesses high
degree of the linear polarization along preferred crystallographic axis which
can be controlled by the lateral voltage applied in the plane of the p(+)-n
junction. Such behavior together with the temperature dependence of the EL
intensity is attributed to the presence of the self-compensating dipole boron
centers, B(+)-B(-), with negative correlation energy which are identified using
the ESR technique in the nanoscale silicon p(+)-n junctions heavily doped with
boron. The model of the recombination process though the negative-U dipole
boron centers controlling the optical properties of the nanoscale silicon
p(+)-n junctions is proposed.
