The photoabsorption characteristics of GaAs:N δ-doped superlattices (SLs) are investigated. Periodic insertion of N δ-doped layers into GaAs induces the formation of conduction subbands E+ and E-, and each conduction subband forms SL minibands with the GaAs conduction band between the δ-doped layers. In addition to an optical absorption related to the E- band, an abrupt absorption edge originating from the electron transition between the valence band and an E+-related miniband is observed at 1.6eV in a photoluminescence excitation (PLE) spectrum, indicating that GaAs:N δ-doped SLs are promising candidates for the absorber of intermediate-band solar cells.
ASJC Scopus subject areas
- Physics and Astronomy(all)