Correlation-length dependence of lifetime ratios: Individual estimation of interface profile parameters

Abstract

We show that the ratio between relaxation lifetimes dominated by roughness-related scatterings in heterostructures is a well-defined function of the correlation length. Thus, we propose an efficient method for individual estimation of the two size parameters of interface profiles from transport data. Instead of the normal simultaneous fitting of both parameters to lifetimes, we adopt a two-step procedure of (i) inferring the correlation length from some lifetime ratio and then (ii) fitting the roughness amplitude to some lifetime. Similarly, the ratio of roughness-induced linewidths in intersubband absorption may give such an estimation from optical data.

Three-dimensional interface roughness in layered semiconductor structures and its effect on intersubband transitions

“…All fitted η's reside within the range of experimental result. For the correlation length λ, proper experimental measurement methods are still under discussion, with large uncertainty found in the reported values (14Å ∼ 120Å) in the more studied materials 35,[39][40][41] . It is worthy to note that in our model the energy shift and the broadening provide two constraints, which enable simultaneous fitting of η and λ.…”