Copper indium diselenide (CuInSe2) is a prototype ternary compound and group I–III–VI semiconductor with useful optoelectronic properties. CuInSe2 nanocrystals have been of significant interest because of their size-tunable optical properties and lack of toxic heavy metals. Because of the particular vacancy and antisite substitutional point defects in CuInSe2, large stoichiometric deviations can be tolerated, sometimes leading to the so-called ordered vacancy compounds (OVCs). Here, we use Raman spectroscopy of oleylamine-capped CuInSe2 nanocrystals and ab initio lattice dynamics modeling to study the concentration and arrangements of (2vCu – + InCu 2+) defect pairs in the nanocrystals. The nanocrystals have randomly distributed defect pairs that become mobile under light excitation and accumulate, as in OVCs, along the [100] direction. Because the high concentration of vacancies in CuInSe2 nanocrystals is compensated by InCu 2+ antisite defects, these nanocrystals do not exhibit an optical plasmon resonance like many other copper chalcogenide nanocrystals. Annealing the nanocrystals at a high temperature (600 °C) was found to significantly reduce the defect concentration.

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Mineralogical characteristics of coastal sediments and their spectral characteristics related to moisture content were analysed for South Korea in this study, and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) shortwave infrared (SWIR) remote sensing approaches for moisture content mapping based on conventional SAM module were proposed in this study. The mineral composition included the major minerals of quartz, alkali feldspar, plagioclase and calcite and the accessary minerals of mica and clay. The absorption features of coastal sediments studied occurred at wavelengths of 1.900 μm for clay minerals and water, 2.200 μm for clay minerals and 2.350 μm for micas and calcite. The spectral signature changed with increased moisture content as the absorption feature at 2.200 μm and 2.350 μm faded out. The fading absorption features shifted the resampled laboratory spectra in a spectral vector space and enabled the use of a SAM module for the ASTER SWIR data. The SAM method effectively distinguished not only the absolute moisture content distribution using the reference spectra but also the relative moisture content distribution without the actual reference spectra for coastal sediments. Given that mineral composition and absorption feature behaviours with regard to the moisture content of soil samples are similar to coastal sediments, this method may be applicable for soil moisture mapping.