Elastic and inelastic tunneling of photoelectrons from the dimensional quantization band at a p(+)-GaAs-(Cs,O) interface into vacuum

The photoemission of electrons from a p(+)-GaAs surface with negative elect ron affinity was studied experimentally at 4.2 K. A narrow peak and its pho non replicas were observed in the distribution of emitted electrons over th e energies of longitudinal motion. These replicas are caused by elastic and inelastic electron tunneling from the bottom of the dimensional quantizati on band in the near-surface spatial-charge region through the potential bar rier of the (Cs,O) activating coverage with emission of LO phonons. The mea sured position of the peak corresponding to elastically tunneling electrons is close to the calculated one. (C) 2000 MAIK "Nauka/Interperiodica".