In the late 1960s, red and the low green LEDs and the infrared semiconductor lasers had already been developed, but there was no prospect of practical blue light emitters, even in the '70s.
Very many researchers, including the front runners in gallium nitride, abandoned the development of gallium nitride-based devices. I have devoted myself to the study of crystal growth, aiming at the development of the p-n junction of gallium nitride.
