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Group V doping in CdSeTe device can improve power conversion efficiency (PCE) and device stability. Arsenic (As) incorporation into CdSeTe has been demonstrated via both in situ and ex situ techniques; however, optimizing the back contact for group V‐doped CdSeTe devices remains a critical challenge. Here, solution‐processed arsenic chalcogenides (i.e., As₂Te₃and As₂Se₃) as dual‐role materials, serving as both dopants and back‐contact materials for high‐efficiency CdSeTe devices, are investigated. During the formation of the back contact, a portion of the arsenic chalcogenides diffuses into the CdSeTe absorber, facilitating p‐type doping. The remaining materials forms a stable back‐contact layer that facilitate carrier collection and reducing recombination losses at the CdSeTe back surface. Particularly, CdSeTe device employing Te rich As₂Te₃layer as the dopant and back‐contact materials achieves a PCE of 18.34%, demonstrating the dual functionality of solution‐processed arsenic chalcogenides in simultaneously doping the absorber and optimizing charge extraction. This solution based cost‐effective As doping approach offers a promising pathway for advancing CdSeTe photovoltaic technology. 

Antimony selenide (Sb2Se3) is a promising material for solar energy conversion due to its low toxicity, high stability, and excellent light absorption capabilities. However, Sb2Se3 films produced via physical vapor deposition often exhibit Se-deficient surfaces, which result in a high carrier recombination and poor device performance. The conventional selenization process was used to address selenium loss in Sb2Se3 solar cells with a substrate configuration. However, this traditional selenization method is not suitable for superstrated Sb2Se3 devices with the window layer buried underneath the Sb2Se3 light absorber layer, as it can lead to significant diffusion of the window layer material into Sb2Se3 and damage the device. In this work, we have demonstrated a rapid thermal selenization (RTS) technique that can effectively selenize the Sb2Se3 absorber layer while preventing the S diffusion from the buried CdS window layer into the Sb2Se3 absorber layer. The RTS technique significantly reduces carrier recombination loss and carrier transport resistance and can achieve the highest efficiency of 8.25%. Overall, the RTS method presents a promising approach for enhancing low-dimensional chalcogenide thin films for emerging superstrate chalcogenide solar cell applications. 

Antimony chalcogenides (Sb₂X₃, where X = S, Se, or S_xSe_1−x) are promising materials for thin‐film solar cells due to their tunable bandgaps (1.1–1.8 eV), high absorption coefficients (>10⁵cm⁻¹), nontoxicity, and earth‐abundant composition. Recent advancements have achieved power conversion efficiencies (PCEs) exceeding 10%, with a record of 10.81% for Sb₂(S, Se)₃cells. However, interface‐related issues, such as recombination losses and open‐circuit voltage (V_OC) deficits, limit performance. Interface engineering strategies have significantly improved device efficiency and stability, including buffer layer optimization, defect passivation, surface treatments, post‐processing, and doping. This review summarizes the latest developments in these areas, discusses ongoing challenges, and proposes future research directions to enhance the performance of antimony chalcogenide solar cells. 

Abstract 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%. 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.