Antimonide

About: Antimonide is a research topic. Over the lifetime, 972 publications have been published within this topic receiving 10981 citations. The topic is also known as: antimonides.

Development of Antimonide-based Energy-sensitive Radiation Detectors

Abstract: Author(s): Juang, Bor-Chau | Advisor(s): Huffaker, Diana L | Abstract: This dissertation is devoted to studying radiation response of the antimonide (Sb)-based detectors and investigating the energy-resolving capability of the integrated GaSb/AlAsSb device structures for X-ray and gamma-ray spectrometry. Energy-sensitive radiation detectors have been extensively employed in applications including material characterization, biomedical research, and homeland security. The unique properties of Sb-based materials could enable an increased flexibility in using the technology for versatile applications. This work attempts to take advantage of Sb-based materials and utilize the heterostructure device concept to achieve this type of radiation detectors. The device development begins with investigating the radiation response of GaSb PIN device, and the energy-sensitive detection has been demonstrated for the first time. With a measurement temperature of 140 K, the device exhibits a full-width-at-half-maximum (FWHM) of 1.238 keV and 1.789 keV at 5.9 keV and 59.5 keV, respectively. The obtained energy resolution has been studied in detail to provide feedback on device design consideration. The heterostructure device architecture has been first approached with the GaSb/GaAs material system using the interfacial misfit (IMF) technique. While the devices show a low dark current floor at room-temperature, the potential barrier induced by the interface charges at the IMF arrays has prevented the effective collection of the carrier generated in the GaSb absorber. The lattice-matched AlAsSb alloy is then investigated as an alternative candidate to replace GaAs for the large-bandgap junction region. Digital-alloy growth of AlAsSb has been developed and gives enhanced optical and electrical characteristics in comparison to the traditional random-alloy growth. Finally, the heterostructure device for energy-sensitive radiation detection has been realized by integrating the GaSb absorber and the AlAsSb digital-alloy combined with a field-control layer to optimize the electric field profile. Well-defined X-ray and gamma-ray photopeaks are successfully obtained by the GaSb/AlAsSb devices under exposure to 241Am radioactive sources. The spectroscopic characterization shows improvement in the extracted excess noise component in comparison to the PIN structure by effectively eliminating the high peak electric field and surface recombination. The minimum FWHM of 1.283 keV at 59.5 keV has been achieved, and measured energy resolution is limited by the noise from the readout electronics rather than the detector material.

Investigation of emitter size effect in InP/InGaAsSb/InGaAs double heterojunction bipolar transistors

Abstract: The emitter size effect of a series InGaAsSb base series of InP/InGaAsSb/InGaAs heterojunction bipolar transistors (HBTs) with different emitter sizes is investigated. Compared to the InGaAs base HBTs, these devices exhibit much lower base surface recombination current. This is attributed to the surface Fermi level pinning near the valence band of the antimonide base. The effect of Sb composition and doping concentration of the base on the surface recombination current is well explained by the postulate.

Antimony-based double junction lamination solar cell and preparation method thereof

Abstract: The invention provides an antimony-based double junction lamination solar cell and a preparation method thereof. The solar cell comprises an antimony sulfide top cell and an antimony selenide bottom cell. According to different deposition orders of two antimonide subcells, the cell is divided into a positive structure and a reverse structure. The solar cell is characterized in that the structure of the antimony-based double junction lamination solar cell is novel; the band gap of antimony sulfide and antimony selenide materials is close to the optimal band gap combination of the top cell and the bottom cell of the double junction lamination solar cell; short-wave light and long-wave light of the solar spectrum can be absorbed separately; the raw materials of two antimony-based compounds are rich and non-toxic; film preparation is simple; the material properties are similar; processes are compatible with each other; and the lamination cell has the advantages of high efficiency, effectively reduced production cost and broad industrialization prospect.

Protection of photocathodes with thin films

Abstract: This invention discloses a thin-film-coated photocathode, including a photocathode formed of first material consisting of potassium cesium antimonide and a thin-film coating of a second material consisting of cesium bromide (CsBr).