Intersubband transition energy and linewidth modified by a submonolayer AlAs insertion into GaAs quantum wells

摘要

We demonstrate a modification of the energy and linewidth of intersubband transitions by the hetero-insertion of a submonolayer into semiconductor quantum wells (QWs). Different changes in the transition energy and absorption linewidth are observed with systematically varied positions of a 0.92-monolayer AlAs insertion into 7.0-nm-wide GaAs QWs. The experimental results are well reproduced by theoretical calculations taking into account energy shifts and scattering processes in electron subbands due to the hetero-insertion. Our findings suggest that the combination of the insertion position and well width can be used to separately tune the transition energy and absorption/emission linewidth for optoelectronic devices.