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.

Single-Crystal Alkali Antimonide Photocathodes: High Efficiency in the Ultrathin Limit

Abstract: The properties of photoemission electron sources determine the ultimate performance of a wide class of electron accelerators and photon detectors. To date, all high-efficiency visible-light photocathode materials are either polycrystalline or exhibit intrinsic surface disorder, both of which limit emitted electron beam brightness. In this Letter, we demonstrate the synthesis of epitaxial thin films of Cs_{3}Sb on 3C-SiC (001) using molecular-beam epitaxy. Films as thin as 4 nm have quantum efficiencies exceeding 2% at 532 nm. We also find that epitaxial films have an order of magnitude larger quantum efficiency at 650 nm than comparable polycrystalline films on Si. Additionally, these films permit angle-resolved photoemission spectroscopy measurements of the electronic structure, which are found to be in good agreement with theory. Epitaxial films open the door to dramatic brightness enhancements via increased efficiency near threshold, reduced surface disorder, and the possibility of engineering new photoemission functionality at the level of single atomic layers.

Type II superlattice barrier infrared detector

Abstract: Significant progress has been achieved in the antimonide-based type-II superlattices since the analysis by Smith and Mailhiot in 1987 first pointed out their advantages for infrared detection. In the long-wavelength infrared (LWIR), type-II InAs/Ga(In)Sb superlattices have been shown theoretically to have reduced Auger recombination and suppressed band-to-band tunneling. Suppressed tunneling in turn allows for higher doping in the absorber, which has led to reduced diffusion dark current. The versatility of the antimonide material system, with the availability of three different types of band offsets, provides great flexibility in device design. Heterostructure designs that make effective use of unipolar barriers have demonstrated strong reduction of generation-recombination (G-R) dark current. As a result, the dark current performance of antimonide superlattice based single element LWIR detectors is now approaching that of the state-of-the-art MCT detector. To date, the antimonide superlattices still have relatively short carrier lifetimes; this issue needs to be resolved before type-II superlattice infrared detectors can achieve their true potential. The antimonide material system has relatively good mechanical robustness when compared to II-VI materials; therefore FPAs based on type-II superlattices have potential advantages in manufacturability. Improvements in substrate quality and size, and reliable surface leakage current suppression methods, such as those based on robust surface passivation or effective use of unipolar barriers, could lead to high-performance large-format LWIR focal plane arrays.

Removable organic protective coating for alkali-antimonide photocathodes

Abstract: We describe a technique for protecting alkali-antimonide visible light photocathodes against deterioration by exposure to impurities, during handling or storage in poor vacuum or gas. The photocathodes are coated with a ∼1 μ m vacuum-deposited hexatriacontane film, which can be subsequently removed by low-temperature sublimation . We show that Cs 3 Sb coated photocathodes can be exposed for several minutes to considerable amounts of oxygen, without deterioration. Their initial photoemission properties are almost fully recovered after film removal.

Development of an electronic device quality aluminum antimonide (AlSb) semiconductor for solar cell applications

Abstract: Electronic device quality Aluminum Antimonide (AlSb)-based single crystals produced by controlled atmospheric annealing are utilized in various configurations for solar cell applications. Like that of a GaAs-based solar cell devices, the AlSb-based solar cell devices as disclosed herein provides direct conversion of solar energy to electrical power.