The results of numerical and experimental study of the electric field strength, photoluminescence wavelength, and internal quantum efficiency of InGaN/GaN (0001) blue LED heterostructures consisting of InGaN multiple quantum wells and GaN barrier layers with the thicknesses of 3, 10, and 15 nm are presented. It is shown that a decrease in the thicknesses of the GaN barrier layers results in a blue shift of the wavelength of LED structures and in an increase of internal quantum efficiency of the structure at high excitation power density.