Abstract This paper has clarified the light emitting diode and laser diode system behaviour description and their external quantum efficiency measurements. Light output of LED spontaneous emission and laser diode stimulated emission are clarified. Stimulated and amplified spontaneous emission of laser diode and LED system configuration are demonstrated. The management of hybrid light sources spectrum illumination interaction for efficient solar cells light intensity and short circuit current density enhancement. The laser diode has presented better performance in the light output power especially under the same temperature effects. It is ensured that the dramatic effects of the temperature on both laser diode performance efficiency.