Before revision: A high-field domain is a band of elevated field orthogonal to the equi-current lines and seen in photoconductive and monochromatic light at the band edge as dark band was discovered by Böer,Karl W. Böer, Z. Physik 155, 184 (1959) using the Franz-Keldysh effect.
After revision: ,A high-field domain is a band of elevated field orthogonal to the equi-current lines and seen in photoconductive and monochromatic light at the band edge as dark band was discovered by Böer,Karl W. Böer, Z. Physik 155, 184 (1959) using the Franz-Keldysh effect.