ADVANCED FUNCTIONAL MATERIALS
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2021
·Vol. 32
·期 12
·2109891
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IF 18.808
Ganghong Liu,Zehao Zhang,Cuncun Wu,Yuqing Zhang,Xiangdong Li,Wenjin Yu,Guangjie Yao,Shiming Liu,Jun-jie Shi,Kaihui Liu,Zhijian Chen,Lixin Xiao,Bo Qu
The toxicity of lead-based halide perovskites hampers broad application in optoelectronics. Lead-free perovskite Cs 2 AgBiBr 6 is considered a promising candidate, owing to the long carrier lifetime and great stability. However, the relatively large bandgap of 1.98 eV limits its absorption in the visible region. Herein, Fe 2+ is chosen as the dopant to alloy into Cs 2 AgBiBr 6 single crystals, and results in an absorption range broadening to ≈1350 nm, which is the longest near-infrared (NIR) response recorded among lead-free perovskites. About 1% of Fe ions are alloyed into the Cs 2 AgBiBr 6 lattice to cause lattice shrink age. Instead of narrowing the bandgap, Fe doping would introduce a new intermediate band inside the pristine bandgap of Cs 2 AgBiBr 6 to strongly absorb NIR light, as confirmed by third harmonic generation results. Moreover, considerable photogenerated carriers are produced in Fe doped Cs 2 AgBiBr 6 crystals with NIR irradiation. This work has provided a new way to extend the optical response of lead-free perovskites for NIR photodetectors and intermediate band photovoltaics.
研究领域:
材料科学
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光电子学
✓ 已验证
产品关联
DOI
高影响因子
Alexandria Engineering Journal
·
2025
·
IF 6.8
Wenliang Fan,Qinliang Gao,Yingying Yang,Ligang Wang,Yanlai Wang,Haiyan Yao
In order to discuss the intermediate band (IB) formation mechanism, influence on photoelectric conversion, electron transition process and other photovoltaic properties of Ti-doped p-CuGaS 2 light absorption material, p-CuGaS 2 and Ti-doped p-CuGaS 2 were synthesized through low-cost heat injection and annealing. Structural characterization results indicate that Ti 3 + partially replaced Ga 3+ in the Ti-doped p-CuGaS 2 . Two additional sub-band absorption peaks of Ti-doped p-CuGaS 2 confirm the formation of an IB. The band structures are confirmed by optical analysis and ultraviolet photoelectron spectroscopy, and the electron transition processes—from the valence band (VB) to the conduction band (CB), the valence band (VB) to the IB, and the IB to the conduction band (CB)—are analyzed. The IB formation mechanism is discussed using the band structure and theoretical calculations derived from density functional theory. A thin-film solar-cell model with Ti-doped p-CuGaS 2 as the absorbing layer is created. Numerical simulations based on experimental data show that the photoelectric conversion efficiency increase from 15.06 % for CuGaS 2 to 25.46 % for Ti-doped p-CuGaS 2 because of the IB effect, which enhances the optical absorption and extends the spectral response range. In conclusion, the research findings will establish a fundamental basis for the exploration of intermediate-band solar cells based on copper gallium sulfide.
研究领域:
材料科学
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光伏技术
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理论计算
✓ 已验证
产品关联
DOI
高影响因子
Applied Nanoscience
·
2020
·Vol. 10
·期 12
·4415-4426
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IF 2.88
Duan Jihai,Pan Peng,Xue Kang,Zhao Hui,Zhang Zisheng,Wang Weiwen
B-C-N-TiO 2 catalysts with intermediate band gap and heterojunction were prepared by sol–gel method. The crystal structure, elemental composition, and absorbance performance were analyzed by XRD, XPS and UV–vis DRS. Due to the formation of the continuous intermediate band gap in the forbidden band, the optical absorption boundary of B-C-N-TiO 2 catalyst extends to 412 nm, which shows different red shift compared with that of TiO 2 (397 nm), N-TiO 2 (400 nm), B-TiO 2 (402 nm) and C-TiO 2 (403 nm).Meanwhile, the B-C-N-TiO 2 catalyst is a uniform spherical solid particle with exposed (101) and (211) planes. The degradation efficiency of B-C-N-TiO 2 catalyst to methylene blue(MB) was up to 97.82% after 3 h under visible light, which shows different degree of improvement compared with that of TiO 2 (34.8%), N-TiO 2 (79.09%), B-TiO 2 (87.82%) and C-TiO 2 (73.19%). B-C-N-TiO 2 has good stability, and there was still more than 95% degradation efficiency after three degradation cycles. It is also revealed that the incorporation of B-C-N element affects the crystal phase of the catalyst and promotes the generation of heterophase surface heterojunction between (101) and (211). It has certain guiding value for co-doping modification of three elements.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 21
·11437-11443
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IF 7.443
Shusheng Pan,Xiaolin Liu,Min Guo,Siu fung Yu,Haitao Huang,Hongtao Fan,Guanghai Li
Ti3+-doped amorphous TiO2 nanoparticles (a-TiO2:Ti3+), which are an intermediate band semiconductor, were fabricated by high intensity ultraviolet pulsed laser ablation in water. The absorption band of a-TiO2:Ti3+ nanoparticles, which appears between the visible and infrared regions, is much wider than that of the rutile TiO2 nanoparticles. The intermediate band, which has a recombination lifetime of 0.71 μs, is found to be 1.61 eV above the valence band (VB) top of TiO2. It can be shown that the a-TiO2:Ti3+/TiO2 nanotube hybrid dye-sensitized solar cells (DSSCs) not only have a high fill factor and large open circuit voltage, but also have high photovoltaic conversion efficiency as compared to TiO2 nanotube DSSCs. Considering that most of the current solar cells use only a single photoelectric conversion material (PCM), our results will promote the research on multi-PCM hybrid solar cells.
研究领域:
材料科学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）