Efficient Targeted Regulation of the Interfaces and Bulk in Inverted Perovskite Solar Cells With a [closo-B12H12]2--based Derivative

The performance and stability of inverted perovskite solar cells (PSCs) is adversely affected by the recombination loss, ion migration, and residual stress arising from issues within the bulk and at the cathode interface. Using simple post-treatment with a novel solution-processable derivative of the dodecahydro-closo-dodecaborate anion ([closo-B12H12]2-)-(TBA)2[B12H11(OCH2CH2)2OH] (TBA2B)-it is simultaneously address these issues. In inverted PSCs, the cationic and anionic components of TBA2B uniquely self-separate by positioning themselves precisely to perform their specific modification functions. The majority of [B12H11(OCH2CH2)2OH]2- anions reside at the (6,6)-phenyl-C61 butyric acid methyl ester (PCBM)/Ag interface, which enhances the electrical and physical contact. Additionally, a substantial fraction of tetrabutylammonium cations diffuse into the perovskite/PCBM heterojunction, enabling comprehensive control over the trap passivation, stress release, ion migration elimination, and grain boundary reinforcement through the in situ formation of 1D TBAPbI3 on the surface of the perovskite crystals. The TBA2B devices exhibit high power conversion efficiency of 25.59% and open-circuit voltage of 1.199 V, performance that is among the highest achieved with a solution-processed perovskite/PCBM heterojunction. Furthermore, TBA2B significantly enhances the device's stability. This study provides crucial insights into the design of efficient and solution processable [closo-B12H12]2--based interface materials, and offers a comprehensive understanding of the underlying modification mechanisms.

A New Approach to the Synthesis of Nanocrystalline Cobalt Boride in the Course of the Thermal Decomposition of Cobalt Complexes [Co(DMF)6]2+ with Boron Cluster Anions

In the course of the study, nanocrystalline cobalt monoboride was prepared by thermal decomposition of precursors [Co(DMF)₆][An], where [An] = [B₁₂H₁₂]^2- (1), [trans-B₂₀H₁₈]^2- (2) or [B₁₀Cl₁₀]^2- (3) in an argon atmosphere. Three new salt-like compounds 1-3 were prepared when Co(NO₃)₂ was allowed to react with (Et₃NH)₂[An]. Compound 1 is new; the structures of compounds 2 and 3 have been previously reported. Samples 1-3 were annealed at 900 °C in argon to form samples 1a-3a, which were characterized by single crystal XRD for 1 and powder XRD for 1-3. Powder XRD on the products showed the formation of BN and CoB for 1a in a 1:1 ratio; 2a gave a higher CoB:BN ratio but an overall decreased crystallinity. For 3a, only CoB was found. IR spectra of samples 1a-3a as well as X-ray spectral fluorescence analysis for 3a confirmed these results. The nanoparticular character of the decomposition products 1a-3a was shown using TEM; quite small particle sizes of about 10-15 nm and a quite normal size distribution were found for 1a and 2a, while the decomposition of 3 gave large particles with 200-350 nm and a broad distribution.

Synthesis and structural properties of a 2D Zn(II) dodecahydroxy-closo-dodecaborate coordination polymer

In this work, we discuss the synthesis and characterization of a 2D coordination polymer composed of a dianionic perhydroxylated boron cluster, [B12(OH)12]2-, coordinated to Zn(II)—the first example of a transition...