It appears that you are a beginner in microgreens and you need to know the basics. Here is an article that might help.

Microgreens are the plants of 7-25 days with fully mature cotyledons with or without true leaves.

They have high phytochemical concentrations, some have higher phytochemicals than their matured plants.

Could refer to Xiao et al., 2012 and Kalhor et al., 2018

and for effect of LEDs on the plants you could refer to this book titled "Light-emitting diodes in Agriculture ed 2017"