Similar to a photovoltaic panel generating an electric current, semiconductor detectors work in the same way to produce an electric current induced by ionizing radiation. This is how ionizing radiation creates or induces a current within the semiconductor. As ionizing radiation enters the semiconductor, it interacts with the semiconductor material.
Definition
A radiation detection device that works based on solid state like silicon or germanium -usually called a semiconductor- for detecting the effect produced by any incident charged particles or photons would be termed a semiconductor detector. Production of International Chemicals or Organic Compounds that Can Control the Conduction Depending on the Chemical Structure, the Temperature, the Illumination, and the Presence of the Dopants. In other words, a semiconductor is a material whose conductivity falls between that of a metal such as copper or gold, and that of an insulator, such as glass.
Working
Semiconductor detectors can excite an electron out of its energy level and leave a hole. This process is known as the generation of electron-hole pairs. In semiconductor detectors, the fundamental carriers of information are these electron-hole pairs, produced along the path through which a charged particle (primary or secondary) travels through the detector. The detection signal is built and recorded by gathering the electron-hole pairs.
Materials Used
These detectors were created for radiation energy measurements and particle identification. Silicon is mainly the charged particle detectors’ semiconductor material unlike germanium as gamma ray spectrometry applications. The large, clean, and almost perfect semiconductor is the right one for radioactivity counting. These crystals are, however, not easy to grow come in large sizes and great purity. All semiconductor detectors are grossly inefficient but send a very precise measure of the energy. Such detectors, germanium based of course, are most likely found in cases where very good energy resolution is required. Cold liquid nitrogen temperatures will usually be the working conditions for the instruments in order to make measurements at maximum efficiencies (-196 Centigrade). Therefore, the ultimate truth is that now semiconductor detectors are more expensive than other detectors and require costly cooling to eliminate noise due to leakage currents.
Energy Production
Creating electron-hole pairs requires much less energy than creating paired ions in a gaseous ionization detector. With regard to semiconductor detectors, the statistical variation in pulse height is much lower, and so is energy resolution. Since electrons are fast, time resolution is also very good. This is the highest density of any detector; thus, one can have relatively small dimensions in a semiconductor and be able to dissipate energy from high-energy charged particles.
Advantages
- It can record very high-count rates, about 5 * 104 counts/sec easily.
- They are less sensitive to the radiation background.
- They do not have windows to admit charged particles into the detector.
- They have very good energy resolution.
- The height of the pulse is proportional to the kinetic energy of the incoming particles if the range of the incoming particle is less than that of the junction thickness.
- Rise time of the pulse is very small.
- The applied voltage is low compared to gas counters.
This silicon or Germanium diode of the p-n type operated in the reverse bias mode. The applied voltage, aligned with the diffusion field potential, increases the resultant potential drop across the transition region. The width of the depletion layer increases. A very high field of the order of 10,000 V/cm is the major advantage of detectors.
