AFM study of surface morphology in green LED structures and multifractal analysis allowed us to reveal a relationship between step-meandering morphology quantitatively characterized by a multifractal parameter, the degree of disorder, and features of In incorporation in InGaN/GaN MQW structures. These features manifest themselves in a shape of the distribution of peak external quantum efficiency values with wavelengths (DPEW) in the current range of 0.1-1000 mA. High values of degree of disorder result in spinodal alloy decomposition and/or local In enriched regions in InGaN alloy and in a twofold decrease in EQE values in green LEDs.