Digital photography uses cameras containing arrays of electronic photodetectors to capture images focused by a lens. The captured images are digitized and stored as a computer file ready for further viewing, processing and electronic publishing. This technology has revolutionised the way we use image-based media and hundreds of millions of digital cameras have been sold worldwide in the last two decades. A key element in many of these cameras is the charge-coupled device (CCD) sensor. These are semiconductor devices that use a silicon chips to convert light into electrical signals. When light is absorbed by the chip, a single electron is released. Electrodes covering the chip surface hold these electrons in place in an array of wells, or pixels, so that during exposure of the chip to light, a pattern of charge builds up that corresponds to the pattern of light. This is then digitized to generate an image. Willard Boyle was a Canadian physicist who co-invented the CCD detector in the 1960s at the world famous AT&T Bell Labs facility in the USA. For this achievement, he won a share of the 2009 Nobel Prize in Physics.
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The fundamentals of solid state semiconductor devices are studied extensively in the Heriot-Watt physics programme (3rd year course B29SS Solid State Physics, 4th year course B20QD Quantum Theory & Solid State and 5th year course B21OD Semiconductor Optoelectronic Devices). CCD detectors also find application in the field of astronomy – a subject explored in our new 2nd year B28AP Astrophysics course.