{"id":26407,"date":"2020-02-14T17:57:45","date_gmt":"2020-02-14T17:57:45","guid":{"rendered":"http:\/\/sitepourvtc.com\/?page_id=26407"},"modified":"2023-06-28T11:12:11","modified_gmt":"2023-06-28T11:12:11","slug":"semiconductor-detectors","status":"publish","type":"page","link":"https:\/\/sitepourvtc.com\/nuclear-engineering\/radiation-detection\/semiconductor-detectors\/","title":{"rendered":"Semiconductor Detectors"},"content":{"rendered":"
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Silicin Strip Detector Source: micronsemiconductor.co.uk<\/figcaption><\/figure>\n

A semiconductor detector<\/strong> is a radiation detector based on a semiconductor<\/strong><\/a>, such as silicon<\/strong> or germanium,<\/strong> to measure the effect of incident charged particles or photons. In general, semiconductors are materials, inorganic or organic, which can control their conduction depending on chemical structure, temperature, illumination, and presence of dopants. The name semiconductor comes from the fact that these materials have electrical conductivity between a metal, like copper, gold, etc., and an insulator, such as glass. They have an energy gap<\/strong><\/a> of less than 4eV (about 1eV). In solid-state physics, this energy gap or band gap is an energy range between the valence band and conduction band<\/a> where electron states are forbidden. In contrast to conductors, electrons<\/a> in a semiconductor must obtain energy (e.g., from ionizing radiation<\/a>) to cross the band gap and reach the conduction band.<\/p>\n

Semiconductor detectors<\/strong> are very similar in operation to photovoltaic panels that generate electric currents. Similarly, a current can be induced by ionizing radiation. As ionizing radiation enters the semiconductor, it interacts with the semiconductor material, and it may excite an electron<\/strong> out of its energy level and consequently leave a hole. This process is known as electron-hole pair<\/a> generation. In semiconductor detectors, the fundamental information carriers are these electron-hole pairs, which are produced along the path taken by the charged particle (primary or secondary) through the detector. By collecting electron-hole pairs, the detection signal is formed and recorded.<\/p>\n

Semiconductor detectors<\/strong> are widely used in radiation protection<\/a>, an assay of radioactive materials, and physics research because they have some unique features, can be made inexpensively yet with good efficiency, and can measure both the intensity and the energy of incident radiation. These detectors are employed to measure the energy of the radiation and for the identification of particles. If the available semiconductor materials, silicon<\/strong> is mainly used for charged particle detectors<\/strong> (especially for tracking charged particles) and soft X-ray detectors, while germanium<\/strong> is widely used for gamma-ray spectroscopy<\/strong><\/a>. A large, clean, and almost perfect semiconductor is ideal as a counter to radioactivity<\/a>. However, it isn’t easy to make large crystals with sufficient purity. The semiconductor detectors have low efficiency, but they give a very precise measure of energy. Semiconductor detectors, especially germanium-based detectors<\/strong>, are most commonly used where a very good energy resolution is required. The detectors must operate at the very low temperatures of liquid nitrogen (-196\u00b0C) <\/strong>to achieve maximum efficiency. Therefore, the drawback is that semiconductor detectors are much more expensive than other detectors and require sophisticated cooling to reduce leakage currents (noise).<\/p>\n

<\/span>Types of Semiconductors<\/div>
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Types of Semiconductors <\/strong><\/p>\n

There are many semiconductors in nature and others synthesized in laboratories; however, the best known are silicon (Si) and germanium (Ge). Types of semiconductors:<\/p>\n