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Sb2S3 is a promising candidate for the flexible solar cells or the top subcells in tandem solar cells due to its wide-bandgap, less toxic, acceptable cost and progressive power conversion efficiency (PCE). However, the poor quality and high trap states of Sb2S3 films limit the device performance further enhancement. Herein, we adopt a multidentate ionic liquid, tetramethylammonium hexafluorophosphate ([TMA][PF6]) as a novel additive to address this issue. The octahedral [PF6]− contains six different oriented fluorine atoms with the lone pair electrons, which could coordinate with Sb atoms due to the multidentate anchoring. Thus, the high-quality Sb2S3 film with low trap states has been achieved. Moreover, the Fermi level of the Sb2S3 film has been upshifted, thereby showing an effective charge transfer. As a result, all photovoltaic parameters of the optimized Sb2S3 devices are obviously enhanced, boosting the final PCE from 4.43 (control device) to 6.83 %. Our study about the multidentate anchoring is manifested to be an effective method to enhance the Sb2S3 device performance.

The competition between charge recombination and extraction principally affects the fill factor (FF) and power conversion efficiency (PCE) of planar thin-film solar cells. In Sb2S3 thin-film solar cells, the electrocharge recombination and extraction n transport layer (ETL) plays a significant role in electron extraction and determination of Sb2S3 film absorber quality. Herein, a TiO2 ETL is strategically modified using an inorganic salt zinc halide (i.e., ZnCl2, ZnBr2, ZnI2), which simultaneously improves the electronic properties of TiO2 and promotes the growth of Sb2S3 films with larger grain size and higher crystallinity. The experimental results and theoretical calculations further reveal that the zinc halide can interact with TiO2 and simultaneously bond strongly with the upper Sb2S3 film, which creates a unique pathway for electron transfer, passivates the trap states, and alleviates the recombination losses effectively. As a result, an average PCE of 6.87 ± 0.11% and the highest PCE of 7.08% have been attained with an improved FF from 51.22 to 61.61% after ZnCl2 introduction. Additionally, introduction of ZnCl2 helps the unencapsulated devices to maintain 93% of their original performance after 2400 h of storage in a nitrogen-filled glovebox. This work develops an effective route for the optimization of ETLs and defect healing using simple and low-cost inorganic salts.

A star-shaped polymer enables inverted perovskite solar cells with efficiency over 22% and a very high fill factor of 0.862., Stabilizing high-efficiency perovskite solar cells (PSCs) at operating conditions remains an unresolved issue hampering its large-scale commercial deployment. Here, we report a star-shaped polymer to improve charge transport and inhibit ion migration at the perovskite interface. The incorporation of multiple chemical anchor sites in the star-shaped polymer branches strongly controls the crystallization of perovskite film with lower trap density and higher carrier mobility and thus inhibits the nonradiative recombination and reduces the charge-transport loss. Consequently, the modified inverted PSCs show an optimal power conversion efficiency of 22.1% and a very high fill factor (FF) of 0.862, corresponding to 95.4% of the Shockley-Queisser limited FF (0.904) of PSCs with a 1.59-eV bandgap. The modified devices exhibit excellent long-term operational and thermal stability at the maximum power point for 1000 hours at 45°C under continuous one-sun illumination without any significant loss of efficiency.

A novel terbium-tetracarboxylate framework with the 5,5&rsquo, (diazene-1,2-iyl)diisophthalic acid (H4abtc) ligand, formulated as [Tb(Habtc)(DMSO)(H2O)2]n (ZTU-5), has been synthesized and structurally characterized. ZTU-5 features a 2D-layered structure constructed by the binuclear terbium secondary building units (SBUs) and abtc4&ndash, ligand, which can be further expanded into a 3D-supramolecular framework by the hydrogen bond interactions. In addition, the magnetic and fluorescence properties of ZTU-5 are investigated and ZTU-5 exhibits highly selective and sensitive detection of nitrofurazone (NZF).