Key Takeaways & Executive Findings
- •• Additive-assisted layer-by-layer (LBL) deposition enables organic solar cells to achieve an unprecedented power conversion efficiency of 20.8%, the highest efficiency to date. • The gradient fibrillar morphology enabled by additive-assisted LBL processing promotes the formation of bulk p-i-n structure, improving exciton and carrier diffusion, and reducing recombination losses. • The wrinkle pattern morphology achieved by additive-assisted LBL processing is constructed to enhance the light capture capability. • This approach offers a solution to achieving high-efficiency devices and demonstrates the potential for commercial applications of OSCs.
Abstract
Recently published in Joule, Feng Liu and colleagues from Shanghai Jiaotong University reported a record-breaking 20.8% power conversion efficiency in organic solar cells (OSCs) with an interpenetrating fibril network active layer morphology, featuring a bulk p-i-n structure and proper vertical segregation achieved through additive-assisted layer-by-layer deposition. This optimized hierarchical gradient fibrillar morphology and optical management synergistically facilitates exciton diffusion, reduces recombination losses, and enhances light capture capability. This approach not only offers a solution to achieving high-efficiency devices but also demonstrates the potential for commercial applications of OSCs.
1. Introduction
Organic solar cells (OSCs) possess the potential for a variety of future applications, including flexible and semi-transparent installations, particularly in the integration with buildings for smart glass windows or device integration, highlighting their unique characteristics. Advancements in polymer donor and non-fullerene acceptor materials have infused the OSC field with renewed optimism [1–3]. These material innovations have significantly broadened the light spectrum absorption range of the active layers and reduced energy losses in devices, leading to a remarkable breakthrough with a power conversion efficiency (PCE) exceeding 19% [4].
In addition, device fabrication and optimization techniques with bulk heterojunction type (BHJ) and layer-by-layer type (LBL) have been greatly improved. The optimal device engineering mainly involves regulating crystallinity and phase separation length scales to improve key morphological parameters in the process of photon-to-electron conversion and transport. The self-assembly behavior of donor/acceptor materials provides a highly crystalline framework for carrier transport channels, reducing the phase size from exciton to carrier processing. However, in BHJ thin-film devices, donor/acceptor blended films can create larger domain areas and poor vertical phase separation, which significantly hinders carrier transport across the films. Compared with the BHJ processing, LBL processing is an effective strategy to address the aforementioned issues. The polymer donor layer at the bottom shows good crystalline connectivity, while the acceptor material partially swells on top, demonstrating a favorable gradient distribution morphology in the vertical direction and thus enabling high performance for OSCs.
Loading authentic research manuscript (Pages 1–5)...
Shuai Xu, Youdi Zhang, Yanna Sun, Pei Cheng, Zhaoyang Yao, Ning Li, Long Ye, Lijian Zuo, Ke Gao (2024). An Unprecedented Efficiency with Approaching 21% Enabled by Additive-Assisted Layer-by-Layer Processing in Organic Solar Cells. Nano-Micro Letters. https://doi.org/10.1007/s40820-024-01529-8
Research & Educational Purpose Only:The translations, structured abstracts, analytical annotations, and data reports provided by SinoTechIntel are intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoTechIntel claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What is the highest power conversion efficiency achieved in organic solar cells as reported in this paper?
The paper reports an unprecedented power conversion efficiency of 20.8% for small-area devices, certified as 20.1%, achieved through additive-assisted layer-by-layer processing.
What is the key morphological feature enabling high efficiency in this study?
The key feature is an interpenetrating fibril network active layer morphology with a bulk p-i-n structure and proper vertical segregation, achieved through additive-assisted layer-by-layer deposition.
How does additive-assisted layer-by-layer processing improve device performance?
It promotes the formation of a gradient fibrillar morphology that enhances exciton and carrier diffusion, reduces recombination losses, and improves light capture capability through a wrinkle pattern morphology.
What are the potential applications of organic solar cells mentioned in the paper?
Organic solar cells have potential for flexible and semi-transparent installations, including integration with buildings for smart glass windows or device integration.
Who are the corresponding authors of this paper?
The corresponding authors are Youdi Zhang, Yanna Sun, and Ke Gao, with contact emails [email protected], [email protected], and [email protected], respectively.
Related Technical Papers & Translations
Direct Repair of the Crystal Structure and Coating Surface of Spent LiFePO4 Materials Enables Superfast Li-Ion Migration
The rapid accumulation of spent LiFePO4 (LFP) cathodes from retired lithium-ion batteries necessitates the development of effective and environmental-friendly recycling strategies. In this context, direct regeneration has emerged as a promising approach for reclaiming LFP cathode materials, offering a streamlined pathway to restore their electrochemical functionality. We report an integrated regeneration protocol that simultaneously repairs the degraded crystal structure and reconstructs the damaged carbon coating in spent LFP. The regenerated cathode material had superfast lithium-ion diffusion kinetics and a stable cathode–electrolyte interface, giving a remarkable rate capability with specific capacities of 122 mAh g−1 at 5C and 106 mAh g−1 at 10C (1C = 170 mA g−1). It also maintained capacities of 110.7 mAh g−1 (5C) and 84.1 mAh g−1 (10C) after 400 cycles. It could be used in harsh environments and could be stably cycled at subzero temperatures (−10 and −20 °C) and in solid-state electrolyte batteries. Life cycle assessment combined with economic evaluation using the EverBatt model reveals that this direct regeneration approach has high economic and environmental benefits.
Oxide Semiconductor for Advanced Memory Architectures: Atomic Layer Deposition, Key Requirement and Challenges
Oxide semiconductors (OSs), introduced by the Hosono group in the early 2000s, have evolved from display backplane materials to promising candidates for advanced memory and logic devices. The exceptionally low leakage current of OSs and compatibility with three-dimensional (3D) architectures have recently sparked renewed interest in their use in semiconductor applications. This review begins by exploring the unique material properties of OSs, which fundamentally originate from their distinct electronic band structure. Subsequently, we focus on atomic layer deposition (ALD), a core technique for growing excellent OS films, covering both basic and advanced processes compatible with 3D scaling. The basic surface reaction mechanisms—adsorption and reaction—and their roles in film growth are introduced. Furthermore, material design strategies, such as cation selection, crystallinity control, anion doping, and heterostructure engineering, are discussed. We also highlight challenges in memory applications, including contact resistance, hydrogen instability, and lack of p-type materials, and discuss the feasibility of ALD-grown OSs as potential solutions. Lastly, we provide an outlook on the role of ALD-grown OSs in memory technologies. This review bridges material fundamentals and device-level requirements, offering a comprehensive perspective on the potential of ALD-driven OSs for next-generation semiconductor memory devices.
Laser powder bed fusion of biodegradable Zn-4Cu alloy: Processing, microstructure and properties
Zn's natural degradability and biocompatibility make it a promising candidate for implants, however, its mechanical properties remain insufficient for bone applications. In this study, the performance of Zn was enhanced by developing Zn-Cu alloys via laser powder bed fusion (LPBF). Optimal LPBF parameters for forming stable tracks were achieved by adjusting laser power and scanning speed. Under optimized conditions of 100 W and 100 mm/s, high-density (99.58%) Zn-Cu alloys with improved hardness (68.2HV) and yield strength (160 MPa) were achieved. These improvements are attributed to solid solution strengthening, segregation strengthening, and grain refinement. The Zn-Cu alloys also demonstrated favorable degradation behavior, with a rate of 0.16 mm/year. This degradation is primarily driven by micro-galvanic corrosion between the CuZn5 phase and Zn matrix, along with refined grains and increased grain boundary density. This work demonstrates a viable strategy for fabricating Zn-based implants with enhanced structural integrity and mechanical performance via LPBF.