# Comments on Spectral Irradiance

## Comments

### Greetings :)

F(λ)=Φ*q*1.24/((λ(μm) *Δλ(μm)), I did not understand how this equation can be developed , here mentioned two values of λ, one is λ(μm) & another one is Δλ(μm), what does that mean , how to develop them .For the homogeneous junction how to calculate this photon flux , what could be the area & how to calculate them :)

### The second formula

I think the first λ(μm) means to calculate the energy of the photon,and the second Δλ(μm) means to the calculation of the energy per μm in specific wave length.

### i think the second Δλ(μm)

i think the second Δλ(μm) means the change in wavelength

### Radiant power density,

For a given wave length, the artificial light delivers less irradiance to that of sunlight.

### Why Spectral irradiance

Why Spectral irradiance increases with wavelength. The equation gives a inverse relation. Thank you.