Fig. 17. (a) Power spectrum density as a function of wavelength for SiC-based LED; (b) the peak of the power spectral density is seen at 480 nm, 534 nm, and 668 nm, respectively. Here, the power spectrum density, which stands for the optical power emitted per unit area per unit energy interval, is represented in W cm⁻¹ eV⁻¹.