Answer to Question #87230 in Electrical Engineering for RAJIV KUMAR KULIYA
One element of a CCD consists of polycrystalline silicon on its bottom, then there's a layer of silicon dioxide for insulating the polycrystalline silicon (p-Si) from three or four contacts. When a positive voltage (directly proportional to exposure to light) is applied to one of the contacts forming a potential well, electrons in p-Si rush to that place, so the charge packets are transferred horizontally from one place of CCD element to another.
To obtain colour signals, a Bayer mask over the CCD is used. The Bayer mask has 4 pixels (2 green, one blue and red) which collect luminance information, and this information depends on voltage applied to the electrodes.