Electron-hole drops in doped silicon

Recombination radiation spectra of Si doped with boron, with the nsub(A) approximately equal to (1017-1019)cm3 acceptor concentration at high excitation levels and circular radiation polarization in a magnetic field at T=1.9 K are studied. It is found that electron-hole drops (EHD) in Si:B exist at nsub(A)<10sup(18) cm-3, and at nsub(A)>10sup(18) cm-3 EHD formation is not beneficial from the energetical point of view. In the nsub(A) approximately equal to (1x1017-5x1017)cm-3 range the paramagnetic dimensional effect in EHD of a small radius, which leads to considerable increase of electron spin susceptibility in the EHD system with the number of electron-hole pairs in EHD of No<102. It is found that silicon radiation at nsub(A)>nsub(C) where nsub(C) approximately 5x1018 cm-3 is a critical concentration of additions of the dielectric-metal transition at high excitation levels is connected with the degenerated nonequilibrium electron-hole plasma (EHP). Appearance of degenerated EHP with the increase of the excitation level at nsub(A)>nsub(C) in the region of the dielectric metal transition is followed by appearance of a new radiation line, which spectral position testifies to existence of a pseudogap in the density of states of holes near the Fermi level. The increase of the EHD density leads to reducing the pseudogap width and increasing the density of states at the Fermi level