G–X electron transfer in GaAsrAlAs type-I superlattices

The photoluminescence PL.and photocurrent Pc.were measured for GaAsrAlAs type-I superlattices under an applied electric field to investigate G–X electron transfer. The PL due to the indirect recombination between the ground X state X1.and the ground heavy-hole state HH1.is clearly observed. In addition, the dips in photocurrent, and enhancement of both intensity and lifetime of the direct PL between the ground G G1.and HH1states are observed at the G1–Xn resonant voltages. These results indicate that G–X electron transfer significantly influences the electron transport, even in type-I superlattices. q1999 Elsevier Science B.V. All rights reserved