A charge-coupled device (CCD) that has been reduced in thickness to improve its quantum efficiency and sensitivity to ultraviolet and infrared light. This is necessary because the electrodes connected to each pixel of a CCD are deposited over the top of the light-sensitive surface and have a restricted light transmission. To overcome this, the silicon chip in which the pixels are incorporated is thinned from its back, by acid etching, until it is typically only 10 μ‎m thick. Light entering from the back of the thinned chip can then reach the pixels more readily. Many CCDs in professional use are thinned.