Heavy pnictogen chalcohalides for efficient, stable, and environmentally friendly solar cell applications

Solar cell technology is an effective solution for addressing climate change and the energy crisis. Therefore, many researchers have investigated various solar cell absorbers that convert Sunlight into electric energy. Among the different materials researched, heavy pnictogen chalcohalides comprising heavy pnictogen cations, such as Bi³⁺and Sb³⁺, and chalcogen-halogen anions have recently been revisited as emerging solar absorbers because of their potential for efficient, stable, and low-toxicity solar cell applications. This review explores the recent progress in the applications of heavy pnictogen chalcohalides, including oxyhalides and mixed chalcohalides, in solar cells. We categorize them into material types based on their common structural characteristics and describe their up-to-date developments in solar cell applications. Finally, we discuss their material imitations, challenges for further development, and possible strategies for overcoming them.

Efficient and Stable Antimony Selenoiodide Solar Cells

Although antimony selenoiodide (SbSeI) exhibits a suitable bandgap as well as interesting physicochemical properties, it has not been applied to solar cells. Here the fabrication of SbSeI solar cells is reported for the first time using multiple spin-coating cycles of SbI3 solutions on Sb2Se3 thin layer, which is formed by thermal decomposition after depositing a single-source precursor solution. The performance exhibits a short-circuit current density of 14.8 mA cm-2, an open-circuit voltage of 473.0 mV, and a fill factor of 58.7%, yielding a power conversion efficiency (PCE) of 4.1% under standard air mass 1.5 global (AM 1.5 G, 100 mW cm-2). The cells retain ≈90.0% of the initial PCE even after illuminating under AM 1.5G (100 mW cm-2) for 2321 min. Here, a new approach is provided for combining selenide and iodide as anions, to fabricate highly efficient, highly stable, green, and low-cost solar cells.

Rare antimony(III) imidazole selone complexes: steric controlled structural and bonding aspects

Novel antimony(iii) imidazole selone complexes in a super crowded environment are reported for the first time. The super bulky selone antimony complexes, [{IPr*Se}(SbCl3)2] (1) and [{IPr*Se}(SbBr3)2] (2), were isolated from the reactions between IPr*Se (IPr*Se = [1,3-bis(2,6-diphenylmethylphenyl)imidazole selone]) and suitable antimony(iii) halides. 1 and 2 are dinuclear complexes with a Sb : Se ratio of 1 : 0.5 with an unusual coordination mode of selone. The molecules 1 and 2 consist of both Menshutkin-type Sbπaryl interactions and a Sb-Se coordination bond. However, the reaction between antimony(iii) halides and [(IPaul)Se] ([(IPaul)Se] = [1,3-bis(2,4-methyl-6-diphenyl phenyl)imidazole selone]) with a spatially defined steric impact gave the dinuclear complex [{(IPaul)Se}(SbCl3)]2 (3) and the mononuclear complex [{(IPaul)Se}(SbBr3)] (4) without Menshutkin-type interactions. The Sb : Se ratio in 3 and 4 is 1 : 1. Interestingly, the Menshutkin-type interaction was absent in 3 and 4 due to the efficient coordinating ability of the ligand [(IPaul)Se] with the Sb(iii) center compared to that of the super bulky ligand IPr*Se. The thermal property of these antimony selone complexes was also investigated. Density functional theory (DFT) calculations were carried out on the model systems [L(SbCl3)2] (1A), [L(SbCl3)] (1B), [L'(SbCl3)2] (1C), and [L'(SbCl3)] (1D), where L = [1,3-bis(2,6-diisopropyl-4-methyl phenyl)imidazole selone] and L' = [1,3-bis(phenyl)imidazole selone], to understand the nature of orbitals and bonding situations. The computed metrical parameters of 1A are in good agreement with the experimental values. Natural population analysis of the model system reveals that the natural charge and total population of antimony(iii) are comparable. The unequal interaction between selenium and antimony obtained using Wiberg bond indices (WBIs) is fully consistent with the findings of the single-crystal X-ray studies.

Solution-synthesis of Sb2Se3 nanorods using KSeCN as a molecular selenium source

Potassium selenocyanate (KSeCN) is used as a molecular selenium source to prepare Sb₂Se₃ nanorods, in which selenocyanate (SeCN⁻) anions are thermally decomposed to elemental Se(0) and then reduced to Se²⁻ anions in the organic amine medium.

An Antimony Selenide Molecular Ink for Flexible Broadband Photodetectors

The need for low-cost high-performance broadband photon detection with sensitivity in the near infrared (NIR) has driven interest in new materials that combine high absorption with traditional electronic infrastructure (CMOS) compatibility. Here, we demonstrate a facile, low-cost and scalable, catalyst-free one-step solution-processed approach to grow one-dimensional Sb₂Se₃ nanostructures directly on flexible substrates for high-performance NIR photodetectors. Structural characterization and compositional analyses reveal high-quality single-crystalline material with orthorhombic crystal structure and a near-stoichiometric Sb/Se atomic ratio. We measure a direct band gap of 1.12 eV, which is consistent with predictions from theoretical simulations, indicating strong NIR potential. The fabricated metal-semiconductor-metal photodetectors exhibit fast response (on the order of milliseconds) and high performance (responsivity ~ 0.27 A/W) as well as excellent mechanical flexibility and durability. The results demonstrate the potential of molecular-ink-based Sb₂Se₃ nanostructures for flexible electronic and broadband optoelectronic device applications.

Organometallically Anisotropic Growth of Ultralong Sb2Se3 Nanowires with Highly Enhanced Photothermal Response

Ultralong orthorhombic Sb2Se3 nanowires have been successfully fabricated via an alternative facile organometallic synthetic route from the reaction of triphenylantimony(III) with dibenzyldiselenide in oleylamine at 180-240 °C without any other additives. The formation and growth mechanism of the Sb2Se3 nanowires is intensively investigated, and it is found that the anisotropic growth of the nanowires with almost constant diameters is resulted from the synergistic effects of the intrinsic property of the orthorhombic crystal structure and the weak binding assistance of oleylamine, and the length of the nanowires can be elongated easily by increasing reaction time in the synthetic route. Moreover, the photothermal response of the Sb2Se3 nanowires is first evaluated under illumination of UV light (320-390 nm), and it is especially noted that the Sb2Se3 nanowires exhibit highly enhanced photothermal responses (more than two times the intensity) as compared to the bulk Sb2Se3. In addition, the Sb2Se3 nanowires show excellent light-to-heat performance, which is superior to that of the nanostructured titanium dioxide and silicon powder under the same conditions.