1. Designing atomic interface in ▫$Sb_2S_3/CdS$▫ heterojunction for efficient solar water splittingMinji Yang, Zeyu Fan, Jinyan Du, Chao Feng, Ronghua Li, Beibei Zhang, Nadiia Pastukhova, Matjaž Valant, Matjaž Finšgar, Andraž Mavrič, Yanbo Li, 2024, original scientific article Abstract: In the emerging Sb2S3‐based solar energy conversion devices, a CdS buffer layer prepared by chemical bath deposition is commonly used to improve the separation of photogenerated electron‐hole pairs. However, the cation diffusion at the Sb2S3/CdS interface induces detrimental defects but is often overlooked. Designing a stable interface in the Sb2S3/CdS heterojunction is essential to achieve high solar energy conversion efficiency. As a proof of concept, this study reports that the modification of the Sb2S3/CdS heterojunction with an ultrathin Al2O3 interlayer effectively suppresses the interfacial defects by preventing the diffusion of Cd2+ cations into the Sb2S3 layer. As a result, a water‐splitting photocathode based on Ag:Sb2S3/Al2O3/CdS heterojunction achieves a significantly improved half‐cell solar‐to‐hydrogen efficiency of 2.78% in a neutral electrolyte, as compared to 1.66% for the control Ag:Sb2S3/CdS device. This work demonstrates the importance of designing atomic interfaces and may provide a guideline for the fabrication of high‐performance stibnite‐type semiconductor‐based solar energy conversion devices. Keywords: alumina, defect passivation, interface engineering, photoelectrochemical water splitting Published in RUNG: 11.03.2024; Views: 1471; Downloads: 3 Full text (4,59 MB) This document has many files! More... |
2. Stable seawater oxidation with a self-healing oxygen-evolving catalystXiaojian Zhang, Chao Feng, Zeyu Fan, Beibei Zhang, Yequan Xiao, Andraž Mavrič, Nadiia Pastukhova, Matjaž Valant, Yi-Fan Han, Yanbo Li, 2023, original scientific article Abstract: Direct seawater electrolysis is key to massive hydrogen fuel production without the depletion of precious freshwater resources and the need for high-purity electrolytes. However, the presence of high-concentration chloride ions (Cl−) and alkaline-earth metal ions (Mg2+, Ca2+) poses great challenges to the stability and selectivity of the catalysts for seawater splitting. Here, we demonstrate a self-healing oxygen evolution reaction (OER) catalyst for long-term seawater electrolysis. By suppressing the competitive chlorine evolution reaction and precipitating the alkaline-earth metal ions through an alkaline treatment of the seawater, stable seawater oxidation is achieved owing to the self-healing ability of the borate-intercalated nickel–cobalt–iron oxyhydroxides (NiCoFe-Bi) OER catalyst under highly-alkaline conditions. The self-healing NiCoFe-Bi catalyst achieves stable seawater oxidation at a large current density of 500 mA cm−2 for 1000 h with near unity Faraday efficiency. Our results have demonstrated strong durability and high OER selectivity of the self-healing catalyst under harsh conditions, paving the way for industrial large-scale seawater electrolysis. Keywords: chemistry, electrocatalysis, seawater oxidation, oxygen evolution reaction Published in RUNG: 08.05.2023; Views: 2010; Downloads: 5 Link to file This document has many files! More... |
3. Coevaporation of doped inorganic carrier-selective layers for high-performance inverted planar perovskite solar cellsJiexuan Jiang, Andraž Mavrič, Nadiia Pastukhova, Matjaž Valant, Qiugui Zeng, Zeyu Fan, Beibei Zhang, Yanbo Li, 2022, original scientific article Abstract: Inorganic carrier selective layers (CSLs), whose conductivity can be effectively tuned by doping, offer low-cost and stable alternatives for their organic counterparts in perovskite solar cells (PSCs). Herein, we employ a dual-source electron-beam co-evaporation method for the controlled deposition of copper-doped nickel oxide (Cu:NiO) and tungsten-doped niobium oxide (W:Nb2O5) as hole and electron transport layers, respectively. The mechanisms for the improved conductivity using dopants are investigated. Owing to the improved conductivity and optimized band alignment of the doped CSLs, the all-inorganic-CSLs-based PSCs achieves a maximum power conversion efficiency (PCE) of 20.47%. Furthermore, a thin titanium buffer layer is inserted between the W:Nb2O5 and the silver electrode to prevent the halide ingression and improve band alignment. This leads to a further improvement of PCE to 21.32% and a long-term stability (1200 h) after encapsulation. Finally, the large-scale applicability of the doped CSLs by co-evaporation is demonstrated for the device with 1 cm2 area showing a PCE of over 19%. Our results demonstrate the potential application of the co-evaporated CSLs with controlled doping in PSCs for commercialization. Keywords: carrier selective layers, Cu-doped nickel oxide, electron-beam evaporation, perovskite solar cells, W-doped niobium oxide Published in RUNG: 17.03.2022; Views: 2952; Downloads: 128 Full text (1,38 MB) This document has many files! More... |
4. Interface engineering of Ta[sub]3N[sub]5 thin film photoanode for highly efficient photoelectrochemical water splittingJie Fu, Zeyu Fan, Mamiko Nakabayashi, Huanxin Ju, Nadiia Pastukhova, Yequan Xiao, Chao Feng, Naoya Shibata, Kazunari Domen, Yanbo Li, 2022, original scientific article Abstract: Interface engineering is a proven strategy to improve the efficiency of thin film semiconductor based solar energy conversion devices. Ta3N5 thin film photoanode is a promising candidate for photoelectrochemical (PEC) water splitting. Yet, a concerted effort to engineer both the bottom and top interfaces of Ta3N5 thin film photoanode is still lacking. Here, we employ n-type In:GaN and p-type Mg:GaN to modify the bottom and top interfaces of Ta3N5 thin film photoanode, respectively. The obtained In:GaN/Ta3N5/Mg:GaN heterojunction photoanode shows enhanced bulk carrier separation capability and better injection efficiency at photo- anode/electrolyte interface, which lead to a record-high applied bias photon-to-current efficiency of 3.46% for Ta3N5-based photoanode. Furthermore, the roles of the In:GaN and Mg:GaN layers are distinguished through mechanistic studies. While the In:GaN layer con- tributes mainly to the enhanced bulk charge separation efficiency, the Mg:GaN layer improves the surface charge inject efficiency. This work demonstrates the crucial role of proper interface engineering for thin film-based photoanode in achieving efficient PEC water splitting. Keywords: photocatalysis, renewable energy Published in RUNG: 09.02.2022; Views: 2852; Downloads: 83 Link to full text This document has many files! More... |