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Materials Used for General Radiation Detection
Published in Alan Owens, Semiconductor Radiation Detectors, 2019
Zinc selenide (ZnSe) belongs to the family of zinc chalcogenides5 (ZnS, ZnSe and ZnTe) whose wide bandgaps make them promising materials for many optoelectronic applications. Of the three, only the selenide has shown a spectroscopic response to X-rays, although ZnTe has been widely used in scintillator applications. Zinc selenide crystallizes in the zincblende configuration. It is a direct bandgap semiconductor with an energy gap of 2.7 eV at room temperature and a density of 5.3 g cm–3. As-grown ZnSe is insulating due to self-compensation but can be made semiconducting by annealing the crystal in molten zinc. It is an interesting material for several reasons. Firstly, its lattice constant is 5.667 Å, which is almost lattice matched to GaAs. This makes epitaxial growth possible. It is also one of the few II-VI compounds for which both n- and p-type materials are available, which has opened up new avenues in optoelectronic applications, such as the production of blue LEDs and laser diodes. For radiation detector applications, ZnSe has been explored as a high-temperature alternative to CdTe and CdZnTe [103] since practical operation of CdTe and CdZnTe detectors is limited to ~70oC before irreversible damage sets in. Similarly, the maximum storage temperatures are around 100oC. ZnSe, by virtue of its large bandgap (2.7 eV as opposed to 1.47 eV for CdTe and 2.0 eV for CdZnTe), should operate to much higher temperatures, up to ~200oC.
Airborne Radiometers to Measure Electromagnetic Radiation in the Earth’s Atmosphere: Mature and Emerging Technologies
Published in John G. Webster, Halit Eren, Measurement, Instrumentation, and Sensors Handbook, 2017
These instruments are composed of three major parts: the optical system, a detector, and a signal processing system (electronics and data acquisition). Furthermore, calibration targets are required that are usually a hot and cold black-body target. An optical window transmits the radiation from the outside atmosphere into the instrument’s optics and to the detector. Zinc selenide (ZnSe) is a common material that has a fairly flat spectral response and transmits radiation across a wide spectral range. Then a filter selects wavelengths; it consists of a narrow band-pass highly transmissive material. Some instruments have individual filters in front of a detector; others use a filter wheel to rotate a selection of filters in front of the detector. Then the light hits the detector (thermal or quantum). Thermal detectors convert the absorbed radiative energy into thermal one. Most thermal detectors do not require cooling but have slow response times and poor detection capability. Quantum detectors usually are faster but often require cooling.
Optical Thin-Film Coatings
Published in Paul Klocek, Handbook of Infrared Optical Materials, 2017
b. ZnSe. Zinc selenide has a slightly higher refractive index than ZnS and does not exhibit as sensitive a sticking coefficient dependence on substrate temperature. Thus, ZnSe can be deposited at higher temperatures. Other than that, it is similar to ZnS and is a very useful material where a higher refractive index is needed. Table 8.11 lists the properties of II—IV and some III—V compound thin films.
Design of a highly efficient FeS2-based dual-heterojunction thin film solar cell
Published in International Journal of Green Energy, 2022
Jaker Hossain, Bipanko Kumar Mondal, Shaikh Khaled Mostaque
In this article, we unravel a novel FeS2-based dual-heterojunction thin film solar cell using ZnSe and AlxGa1-xSb as window and BSF layers, respectively, which exhibits higher efficiency due to suitable band alignments that results in higher built-in potential and hence higher open circuit voltage. Zinc selenide (ZnSe) is a II–VI wide band gap n-type semiconductor with zinc blende structure having a band gap of 2.7 eV and electron and hole mobilities of 50 and 20 cm2·V−1·s−1, respectively, and higher transparency (Krause et al. 1994; Mostefaoui et al. 2015). ZnSe thin films have been deposited by different methods including recrystallization traveling-heater method (RTHM), molecular beam deposition, vacuum evaporation method, atomic layer deposition, electron beam evaporation, electrodeposition, pulsed laser deposition, and chemical bath deposition method (Adachi and Taguchi 1991; Dharmadasa et al. 1999; Guziewicz et al. 2004; C. W. Huang et al. 2008; Li et al. 2010; Patidar et al. 2008; Perna et al. 2002; Poulopoulos et al. 2005).