Properties of the M-1740 P-N Junction Photocell

The p-n junction photocell has a sensitivity of 30 ma per lumen for light of 2,400 degrees K color temperature, corresponding to a quantum yield approximately unity in the spectral range from visible to the long wave cutoff at 1.8 microns. Dark currents of e few microamperes are observed at room temperature, with a temperature coefficient of about + 10 per cent per degree C. Both dark and light currents exhibit saturation in the range from 1 to 90 volts applied. The frequency response is flat into the 100-kc region. Short-circuit noise currents are observed around 20 μμa a in a 1-cps band at 1,000 cps. The photocell element is encapsulated in a plastic housing ¼ × 3/16 × ⅜ inch in dimensions.