Abstract
The single element optical sensor of this invention is a two-terminal element and comprises a light absorbing semiconductor layer, potential barrier materials positioned in said light absorbing layer and two electrodes connected to said light absorbing layer. Positions and chemical compositions of the potential barriers are adjusted according to wavebands of interests. Under different bias conditions photoelectric voltages with separated peaks are generated by the invented optical sensor, whereby color elements of an image may be obtained. Distinguish of light waves of selected wavebands may thus be achieved.