I am using a 2 inch LCS 100 integrated sphere to characterize OLED. But the system is giving the value in lumens. What is the value of solid angle should I take while converting that to candela per m2. Also how to calculate the EQE and IQE. Please help.
Hi Dipjyoti
Look at link
Lumens to candela calculation
For uniform, isotropic light source, the luminous intensity Iv in candela (cd) is equal to the luminous flux Φv in lumens (lm),
divided by the solid angle Ω in steradians (sr):
Iv(cd) = Φv(lm) / Ω(sr)
The solid angle Ω in steradians (sr) is equal to 2 times pi times 1 minus cosine of half the cone apex angle θ in degrees (º):
Ω(sr) = 2π(1 - cos(θ/2))
The luminous intensity Iv in candela (cd) is equal to the luminous flux Φv in lumens (lm),
divided by 2 times pi times 1 minus cosine of half the apex angle θ in degrees (º):
Iv(cd) = Φv(lm) / ( 2π(1 - cos(θ/2)) )
So
candela = lumens / ( 2π(1 - cos(degrees/2)) )
Or
cd = lm / ( 2π(1 - cos(º/2)) )
Jan Grzegorek
http://www.rapidtables.com/calc/light/lumen-to-candela-calculator.htm
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science