Light source for plant cultivation

A plant cultivation light source, comprising:

• a first light emitter having a first energy band gap of a first active layer,
• a second light emitter having a second energy band gap of a second active layer, and
• a third light emitter having a third energy band gap of a third active layer,
• a controller operable to turn on one or more of the first, second, and third light emitters during each of a plurality of light periods,
• wherein the first energy band gap has longer peak wavelength than the second energy band gap,
• wherein the first energy band gap has longer peak wavelength than the third energy band gap,
• wherein the plurality of light periods comprises a first light period and a second light period, and
• wherein at least one of the first, second, third light emitter is off depending on a growth mode of the plant during the second light period.

A plant cultivation device comprising:

• a housing having an inner space capable of growing plants;
• a light source disposed on the housing and configured to emit light into the inner space;
• and
• a controller disposed on the housing and operable to turn on one or more emitters in the light source during a light period,
• wherein the light source includes:
• a first light emitter having a first active layer emitting light having a first peak wavelength within a first color wavelength band range,
• a second light emitter having a second active layer emitting light having a second peak wavelength within a second wavelength band range, and
• a third light emitter having a third active layer emitting light having a third peak wavelength different to the second peak wavelength,
• wherein the controller operates the light source to provide a light having a first spectral pattern,
• wherein the first spectral pattern includes the first peak wavelength having a relatively high intensity and the third peak wavelength having a lower intensity than the first peak wavelength, and
• wherein at least one of the first, second, and third light emitters is off during a light period for at least one of a plurality of growth modes of the plants.