Which cell has the highest sensitivity (current per unit of luminous flux)?
Which cell has the highest sensitivity (current per unit of luminous flux)?
Right Answer is:
Germanium junction photo-conductive cell
SOLUTION
- Photo-conductive cells, in which an incident photon removes an electron from the valence band into the conduction band.
- The value of the forbidden energy gap sets a long wave limit to the sensitivity of the photocell.
- A photoconductive cell appears as a linear resistance, which decreases with increased illumination.
- Photo-conductive diodes operate with a reverse voltage of up to 100 V.
- The germanium junction photodiode has a maximum sensitivity of about 30mA/lumen at a light wavelength of 1.6 µ (or 16,000 A).