New Photoelectric Devices Utilizing Carrier Injection

The detection of injected carriers by their absorption and by emission due to their recombination with majority carriers is discussed. Two new components are proposed: (1) the "photo-modulator," which permits modulation of a light beam by the change in absorption due to injected carriers (the photomodulator in connection with a phototransistor, or some other type of photocell, may be useful as an amplifier); and (2) the "graded seal junction," which permits the light to be transmitted to and from a p-n-junction without substantial absorption in the bulk semiconductor.