Γ–X electron transfer in GaAs/AlAs type-I superlattices

The photoluminescence (PL) and photocurrent (Pc) were measured for GaAs/AlAs type-I superlattices under an applied electric field to investigate Γ – X electron transfer. The PL due to the indirect recombination between the ground X state ( X 1 ) and the ground heavy-hole state (HH 1 ) is clearly observed. In addition, the dips in photocurrent, and enhancement of both intensity and lifetime of the direct PL between the ground Γ ( Γ 1 ) and HH 1 states are observed at the Γ 1 – X n resonant voltages. These results indicate that Γ – X electron transfer significantly influences the electron transport, even in type-I superlattices.