Which component within photoelectric detectors generates an electric current?

The component within photoelectric detectors that generates an electric current is the semiconductor material. In photoelectric detectors, such as photodiodes and phototransistors, the semiconductor is crucial because it allows for the conversion of light energy (photons) into electrical energy (an electric current). When light hits the semiconductor material, it excites electrons, creating electron-hole pairs. This process allows the device to respond to light by producing a measurable electric current, which can then be processed or utilized in various applications.

The other options, while important to the overall functionality of the device, do not play a direct role in generating an electric current. The lens system primarily focuses and directs light onto the semiconductor, while the display unit is used for visual output of signals and the filter system modifies the light spectrum that reaches the semiconductor. Neither of these components is responsible for the conversion of light to electrical energy.