Evidence of Two Disorder Scales in Ga(AsBi), S. Imhof, C. Wagner, A. Chernikov, M. Koch, K. Kolata, N. S. Koster, S. Chatterjee, S. W. Koch, X. Lu, S. R. Johnson, D. A. Beaton, T. Tiedje, O. Rubel, A. Thranhardt Phys. Stat. Sol. (b) 248, 851-854 (2011)

Temperature-dependent photoluminescence in a Ga(AsBi) structure is modelled in an excitonic hopping model and compared to experiment. It is shown that theory and experiment cannot be brought into agreement when using a single energy scale. Thus, a second energy scale is introduced, resulting in a good agreement between theory and experiment. The two scales are identified with spatially large alloy disorder and additional cluster states subdividing this first scale.