Finally, F10 F12 are narrow triband illuminants consisting of three " narrowband " emissions ( caused by ternary compositions of rare-earth phosphors ) in the R, G, B regions of the visible spectrum.
2.
Ternary compositions allow adjusting the band gap within the range of the involved binary compounds; however, in case of combination of direct and indirect band gap materials there is a ratio where indirect band gap prevails, limiting the range usable for optoelectronics; e . g.
मोबाइल