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NCdN(Br)2 crystallizes in the orthorhombic Cmmm space group. The structure is zero-dimensional and consists of four hydrobromic acid molecules and two NCdN clusters. In each NCdN cluster, Cd2+ is bonded in a linear geometry to two equivalent N3- atoms. Both Cd–N bond lengths are 2.57 Å. N3- is bonded in a single-bond geometry to one Cd2+ atom.
CdCl2N2 crystallizes in the orthorhombic Cmmm space group. The structure is one-dimensional and consists of four ammonia molecules and two CdCl2 ribbons oriented in the (0, 0, 1) direction. In each CdCl2 ribbon, Cd2+ is bonded in a square co-planar geometry to four equivalent Cl1- atoms. All Cd–Cl bond lengths are 2.57 Å. Cl1- is bonded in an L-shaped geometry to two equivalent Cd2+ atoms.
CdN(NBr2)3 crystallizes in the monoclinic C2/c space group. The structure is one-dimensional and consists of twelve dibromamine molecules and two CdN ribbons oriented in the (0, 0, 1) direction. In each CdN ribbon, Cd2+ is bonded in a linear geometry to two equivalent N1+ atoms. Both Cd–N bond lengths are 1.99 Å. N1+ is bonded in a linear geometry to two equivalent Cd2+ atoms.
Cd1Mo6S8 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Mo+2.33+ is bonded to five S2- atoms to form a mixture of edge and corner-sharing MoS5 square pyramids. There are a spread of Mo–S bond distances ranging from 2.42–2.51 Å. Cd2+ is bonded in a distorted body-centered cubic geometry to eight S2- atoms. There are two shorter (2.46 Å) and six longer (3.25 Å) Cd–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 1-coordinate geometry to three equivalent Mo+2.33+ and one Cd2+ atom. In the second S2- site, S2- is bonded in a 5-coordinate geometry to four equivalent Mo+2.33+ and one Cd2+ atom.
Cd1Mo6Se8 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Mo+2.33+ is bonded to five Se2- atoms to form a mixture of edge and corner-sharing MoSe5 square pyramids. There are a spread of Mo–Se bond distances ranging from 2.54–2.72 Å. Cd2+ is bonded in a body-centered cubic geometry to eight Se2- atoms. There are two shorter (2.64 Å) and six longer (3.27 Å) Cd–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 1-coordinate geometry to three equivalent Mo+2.33+ and one Cd2+ atom. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to four equivalent Mo+2.33+ and one Cd2+ atom.
CdN10(C)60N2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two ammonia molecules, sixty medicinal charcoal molecules, and one CdN10 cluster. In the CdN10 cluster, Cd2+ is bonded in an octahedral geometry to six N3- atoms. There are a spread of Cd–N bond distances ranging from 2.15–2.19 Å. There are five inequivalent N3- sites. In the first N3- site, N3- is bonded in a single-bond geometry to one Cd2+ atom. In the second N3- site, N3- is bonded in a single-bond geometry to one Cd2+ and one N3- atom. The N–N bond length is 3.27 Å. In the third N3- site, N3- is bonded in a 1-coordinate geometry to two N3- atoms. The N–N bond length is 3.38 Å. In the fourth N3- site, N3- is bonded in a single-bond geometry to one Cd2+ and two N3- atoms. The N–N bond length is 3.14 Å. In the fifth N3- site, N3- is bonded in a single-bond geometry to one N3- atom.
CdN(NCl2)3 crystallizes in the trigonal R-3c space group. The structure is one-dimensional and consists of eighteen dichloramine molecules and three CdN ribbons oriented in the (0, 0, 1) direction. In each CdN ribbon, Cd2+ is bonded in a linear geometry to two equivalent N1+ atoms. Both Cd–N bond lengths are 1.99 Å. N1+ is bonded in a linear geometry to two equivalent Cd2+ atoms.
CdI4(N2)2 crystallizes in the monoclinic C2/m space group. The structure is one-dimensional and consists of eight ammonia molecules and two CdI4 ribbons oriented in the (1, 0, 1) direction. In each CdI4 ribbon, Cd2+ is bonded in a linear geometry to two equivalent I1- atoms. Both Cd–I bond lengths are 2.75 Å. There are two inequivalent I1- sites. In the first I1- site, I1- is bonded in a single-bond geometry to one Cd2+ and one I1- atom. The I–I bond length is 3.36 Å. In the second I1- site, I1- is bonded in a distorted linear geometry to two I1- atoms. The I–I bond length is 2.80 Å.
(Cd)2N2(NBr2)6 crystallizes in the trigonal R-3c space group. The structure is zero-dimensional and consists of six ammonia molecules, six cadmium molecules, and eighteen dibromamine molecules.
CdN(NCl2)3 crystallizes in the trigonal R-3c space group. The structure is one-dimensional and consists of eighteen dichloramine molecules and three CdN ribbons oriented in the (0, 0, 1) direction. In each CdN ribbon, Cd2+ is bonded in a linear geometry to two equivalent N1+ atoms. Both Cd–N bond lengths are 1.98 Å. N1+ is bonded in a linear geometry to two equivalent Cd2+ atoms.
(Cd)2N2(NO2)6 is Cyanogen Chloride-like structured and crystallizes in the cubic Pm-3 space group. The structure is zero-dimensional and consists of one ammonia molecule; one cadmium molecule; and three hydroxylamine, n-hydroxy- molecules.
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Deployment of photovoltaics in space requires devices that combine high-efficiency, low areal mass, and resilience to harsh environments. Historically, high-efficiency multijunction III–V materials have dominated space power systems; however, their high cost and limited manufacturing throughput motivate the exploration of scalable alternatives. While CdTe-based thin-film photovoltaics offer an attractive option, their performance on non-conventional substrates can suffer from front contact instability under higher-temperature processing. Here, the role of front contact chemistry in limiting cell performance is investigated using CdTe-based devices fabricated on 150 μm thick Ceria-doped space-qualified 0214 Corning glass. A matrix of four transparent conducting oxides (TCOs: CTO, AZO, ITO, IZO) combined with two n-type emitters (MZO, IGO) reveals chemical stability at the front interface—rather than absorber composition alone—governs recombination losses, voltage deficits, and device reproducibility. Chemically stable front contact combinations suppress elemental diffusion and interfacial degradation, resulting in significantly improved carrier lifetimes and junction quality. These insights are validated through record-certified Cd(Se,Te) cell efficiencies of 18.4% under AM1.5G and 16.2% under AM0 illumination on ultra-thin glass. Beyond CdTe, this work provides a general framework for the rational selection of TCO/emitter interfaces in superstrate thin-film photovoltaics, including emerging technologies like metal halide perovskites, while enabling high-efficiency, lightweight photovoltaics for space applications.
Random matrix theory (RMT) is used to provide a measure of the chaoticity (q) of calculated results for the spectra for various Cd isotopes. Here, the goal is to gain a better understanding of the internal dynamics in play; namely, whether it tracks with regular or irregular (chaotic) behavior as determined through an RMT analyses of calculated spectra. The basis-state configurations used to determine the spectra includes all positive, negative, natural (J π = 1 – , 2 + , ...), and unnatural parity configurations (J π = 0 – , 1 + , 2 – , ...), unless suppressed for comparative purposes. The results show that when intruder-state configurations are in play, regular behavior emerges, but when not in play, chaotic behavior seems to dominate the dynamics.
The long-term operational stability of perovskite solar cells (PSCs) remains a key challenge impeding their commercialization, particularly due to ambient environments (e.g., moisture, oxygen, heat)-induced degradation. Carbon electrode-based PSCs have emerged as cost-effective and relatively stable alternatives to metal electrode-based devices due to carbon materials' hydrophobic behavior, yet they still lag in both long-term durability and power conversion efficiency (PCE). In this work, an ultrathin hydrophobic ligand-modified core–shell Cd(S,Se)/ZnS quantum dots (QDs) capping layer is introduced as a multifunctional interfacial modifier for carbon-electrode-based PSCs. This oleic acid ligand-modified QDs capping layer exhibits inherent hydrophobicity, effectively serving as a moisture barrier to retard perovskite degradation under ambient conditions. Furthermore, the strong interfacial bonding between the QDs and perovskite halide surfaces leads to efficient trap state passivation, reducing trap density and creating a more uniform electrical contact. The modified QDs/perovskite interface also features an elevated conduction band edge, promoting improved charge extraction. As a result, devices incorporating this quantum dot capping layer retain 98% of their initial PCE after 450 h of ambient aging and achieve a champion efficiency of 20.74%. As a result, this strategy highlights the potential of hydrophobic ligand-modified chalcogenide QDs as surface modifiers to enhance both the stability and performance of carbon-based PSCs, offering a promising route toward scalable fabrication of durable perovskite solar modules.
Magnetic impurities provide a route toward increasing functionality in electronic materials, often enabling new device concepts and architectures. In the case of topological semimetals, dilute magnetic doping presents a particularly attractive approach for inducing a Dirac to Weyl phase change via time reversal symmetry breaking. However, efforts to realize changes in the electronic structure have been limited by challenges in incorporating magnetic impurities into crystals with sufficiently high electron mobilities to detect them via transport or spectroscopic techniques. Here, we demonstrate incorporation of Mn into Cd 3 As 2 Dirac semimetal thin films grown by molecular beam epitaxy (MBE). Using As-rich growth conditions and [001] oriented thin films, Mn compositions of >10% are achieved. Films contain uniform distributions of Mn with no evidence of secondary phases and exhibit electron mobilities greater than 10 000–30 000 cm 2 /Vs up to 5% Mn. An evolution in the magnetization behavior along with the emergence of a second quantum oscillation frequency at low Mn concentrations provide preliminary evidence of Mn-induced changes in the electronic structure that are consistent with a Weyl phase. This work demonstrates the potential of magnetically doping topological semimetal thin films and a pathway for synthesizing them.
The toxicity and instability of lead-based metal halide perovskites are the two main obstacles that prevent perovskite materials from implementation in applications. Recently, layered double perovskites (LDPs) emerge as a new family of perovskite materials which provide a new route to solve these problems by lead-component replacement and reduction of crystal structure dimensionality. However, LDP nanocrystals (NCs) have been rarely studied, limiting the further property exploration and application realization. In this work, we report the colloidal synthesis of a series of Cs 4 Cd 1-x Cu x Sb 2 Cl 12 (0 ≤ x ≤ 1) LDP NCs by tuning the stoichiometry of metal precursors. The composition-structure-property relationships of the resulting LDP NCs are studied through materials characterizations, density functional theory calculations, and transient-absorption spectroscopy. In addition, we demonstrate that high-performance high-speed photodetectors can be fabricated using the colloidal LDP NCs through solution-processing. This work premises further expansion of such LDP-based materials for both fundamental studies and application integrations.
Bond valence sum analysis is a powerful tool used in evaluating and validating crystal structures; especially when those structures are complex in nature. The pyrochlore structure type is versatile in not only the unique bonding that it exhibits, but also in the properties that results from the structure. Here this paper aims to center the discussion of evaluating the pyrochlore structure using the bond valence sum method. In this study, novel quaternary pyrochlores with a general stoichiometry of ABiMTeO 7 (A = Cd, Ca; M = Cr, Ga, Sc, In, Fe) were synthesized and characterized for their structural, magnetic, and dielectric properties. Two representative compounds within this series of pyrochlores, BiCaFeTeO7 and BiCdFeTeO 7 , were structurally characterized utilizing a combination of high-resolution synchrotron X-ray diffraction and neutron diffraction revealing oxygen deficient pyrochlore systems which were off from the expected stoichiometry with respect to the M site. The A site of both pyrochlores were found to be moved off-center from the expected 16d site to the 96h displaced position at a magnitude of 0.25 Å and 0.22 Å for the Bi/Ca and Bi/Cd systems, respectively. These structures were evaluated using the bond valence sum method and compared with trends in the literature. The properties are also reported for the Bi/Ca system for the first time, showing relatively high dielectric constants with a low dielectric loss which are primarily independent of frequency and temperature. The magnetic measurements for the Bi/Ca system for the magnetic substitutions reveal a paramagnet and antiferromagnetic properties for the Fe and Cr analogs, respectively. The novel BiCaMTeO 7 quaternary pyrochlore system shows great promise as an emerging dielectric material.