Si- and Ge-Doped GaAs p-n Junctions

Abstract

Si- and Ge-doped GaAs layers were obtained by a solution regrowth technique. They were p-type and their electric parameters ρ, µH, and p were found depending on the Si or Ge quantities in the melts. Ge-doped crystals had much larger µH values than Si-doped crystals. Si-doped p-n junctions showed I-V characteristics including tunneling and thermal components, while those of Ge-doped junctions had only a thermal component. Si-doped diodes showed photo responses originating from deep acceptor levels, while the photoresponses of Ge-doped ones were derived from a very shallow acceptor level. The same effects were seen in the emission spectra of these diodes. In the Si-doped ones, broad emission peaks were found at the longer wavelengths on account of the deep levels, while the emission spectra of Ge-doped diodes were sharp and concerned with the shallow acceptor level. An emission quantum efficiency of up to 2% was achieved in the Si-doped diode.