Effect of ZnTe transition layer to the performance of CdZnTe/GaN multilayer films for solar-blind photodetector applications

Abstract

High quality CdZnTe films were prepared on GaN substrates by a close-spaced sublimation method and ZnTe transition layers were introduced to decrease the lattice mismatch between substrates and CdZnTe films for the first time. The morphology and structure of multilayer films were measured by x-ray diffraction and scanning electron microscopy. The crystalline quality of CdZnTe films based on ZnTe transition layers is obviously optimized and the best full width at half maximum and grain size of CdZnTe films are 0.149 • and 10.4 µm, respectively. A surface defect analysis of multilayer films was studied by x-ray photoelectron spectroscopy and low temperature photoluminescence, which indicated that the introduction of ZnTe transition layer can reduce the Cd vacancy ratio of CdZnTe films from 22.9% to 13.3%. It is also found that the electrical properties of GaN/ZnTe/CdZnTe multilayer films show a similar PN junction effect and the best photo-dark current ratio reaches 38.8. The responsivity of multilayer films under 254 nm light is about 69.1 times more than that to 400 nm, which improves the detection of CdZnTe films in the solar-blind region effectively.

A review: green chemical mechanical polishing for metals and brittle wafers

“…CZT is a representative of the third generation soft-brittle semiconductors and is used to make radiation detectors. It can also be used as a substrate for epitaxial growth of MCT films [112][113][114]. Surface quality plays a crucial role in the performance of high-resolution HgCdTe and CZT detectors [115].…”

The effects of metal catalytic layer on the performance of CdZnTe thick film

“…The lattice mismatch and thermal expansion coefficient mismatches between CdZnTe films and the usually employed substrate materials, such glass, silicon, limit the formation of higher-quality CdZnTe films [6][7][8] . This problem can be solved by adding buffer layer or catalytic layer between the substrate and the film layer 9,10 . Catalytic layer, as a commonly used method to improve the quality and performance of film layers, has been widely used in the preparation of many materials 11 .…”

Thickness Effect on Some Physical Properties of RF Sputtered ZnTe Thin Films for Potential Photovoltaic Applications

“…Due to characteristics obtained at the time of the deposition process such as: low resistivity, high transparency in the visible spectrum, etc. [ 1 , 2 , 3 , 4 ], thin layers of zinc telluride (ZnTe) are used in various modern technologies, which are implemented in various micro- and nano-structured devices, such as light emitting diodes, solar cells, photodetectors, etc. [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ].…”

“…[ 1 , 2 , 3 , 4 ], thin layers of zinc telluride (ZnTe) are used in various modern technologies, which are implemented in various micro- and nano-structured devices, such as light emitting diodes, solar cells, photodetectors, etc. [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. Although it is a popular material, there are few publications and studies regarding its material engineering.…”

“…The ZnTe thin layer properties depend directly on the deposition method, deposition conditions, and the growth direction imposed by the substrate when the substrate is crystalline [ 5 , 6 , 7 , 8 , 23 ]. Some studies have established the ideal deposition conditions for various deposition methods, to obtain ZnTe layers with the necessary physical properties, a well-defined morphology, and crystal structure, but there is no systematic reproducible technology available for high performance ZnTe coating fabrications [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 24 , 25 ]. In this context, studies regarding correlation for growth conditions/parameters with ZnTe structuring and morphology, in correlation with their physical properties, are still very important.…”