Infrared luminescence from silicon nanostructures heavily doped with boron

Intense highly polarized radiation from silicon nanostructures heavily doped with boron to 5 $\times$ 10$^{21}$ cm$^{-3}$ is studied as a function of temperature, forward current, and an additional lateral electric field. The features of the radiation intensity and degree of polarization suggest that an important role in the formation of the luminescence spectra is played by the ordered system of B$^+$–B$^-$ dipoles, formed as a result of the reconstruction of shallow boron acceptors as centers with negative correlation energy. The results obtained are interpreted within a proposed model based on two-electron adiabatic potentials, according to which radiation results from donor-acceptor recombination via boron dipole center states, involving shallow phosphorus donors.