INVERTED ORDER OF ACCEPTOR AND DONOR LEVELS OF MONATOMIC HYDROGEN IN SILICON

The acceptor level epsilon(A) of monatomic hydrogen (H-2) in crystalli ne silicon has been located at epsilon(A) almost-equal-to epsilon(m) 0.00 eV, where epsilon(m) is the midgap level, more than 0.3 eV below the recently identified donor level. Thus, hydrogen has a large negat ive ''effective Coulomb energy.'' We obtain epsilon(A), via the princi ple of detailed balance, from separately measured electron emission an d capture rates, assuming that the processes H+ + 2e- <--> H- proceed by a brief residence in the ground state of H-. Such routes seem indic ated by ab initio calculations of the energies of H+, H0, and H- for v arious atomic positions and relaxations.