ACS Nano
·
2024
·
IF 15.8
Jing Li,Jianliang Li,Meiqi An,Shuai Yang,Yanan Bao,Hengshan Wang,Huayi Tang,Haotian Wang,Yurui Fang,Jijun Qiu,Jiming Bian,Jiao Xu,Yiming Yang
Anion exchange in halide perovskites offers prospective approaches to band gap engineering for miniaturized and integrated optoelectronic devices. However, the band engineering at the nanoscale is uncontrollable due to the rapid and random exchange nature in the liquid or gas phase. Here, we report a source-limiting mechanism in solid-state anion exchange between low-dimensional perovskites, which readily gives access to ultralong compositional gradient nanowires (NWs) with lengths of up to 100 μm. The exchanged NWs remain single-crystalline with intact morphology, while the halogen content exhibits an apparent gradient distribution, leading to a tapered energy band profile along a NW. In the dynamic study of anion behavior, it is shown that the spatial stoichiometric composition can be precisely tuned following Fick’s law of diffusion. In addition, self-powered, spectrally resolved photodetectors incorporating multiple detection units within a single gradient NW are demonstrated. This work provides a feasible strategy for the realization of perovskite-based ultracompact optoelectronics, imaging sensors, and other miniaturized semiconductor devices.
研究领域:
材料科学
·
光电子学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMISTRY OF MATERIALS
·
2020
·
IF 9.567
Xin Wang,Yuwei Li,Yubing Xu,Yuzhu Pan,Chongyang Zhu,Dianjia Zhu,Yao Wu,Guanwen Li,Qi Zhang,Qing Li,Xiaobing Zhang,Jun Wu,Jing Chen,Wei Lei
Although epitaxial growth is the fundamental method to realize lattice matched heterojunctions in electronics manufacturing, large-scale epitaxial single crystal layers based on solution-processing have rarely been reported. Here, cascade organic–inorganic hybrid perovskite single crystals with purity quotient over 99.9% consisting of chlorine, bromine, and iodine are fabricated by solution-processed epitaxial growth, in which the mismatch rate between adjacent layers is less than 1%. The area of solution-processed epitaxial growth is proved up to 4 cm2, and the speed reaches nearly 100 nm s–1. The resulting high-quality interface effectively improves bonding between adjacent layers, and the average mobility is calculated to be over 200 cm2 V–1 s–1 in samples with different structures. Based on a specific structure with n-type, p-type, and intrinsic layers, a 7.55 mm-thickness X-ray photodiode with sensitivity 1.58 μC mGy–1 cm–2 is fabricated. This work provides a different method for fabricating solution-processed based electronic devices and makes stable perovskite-based devices more accessible.
研究领域:
材料科学
·
电子工程
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
Results in Physics
·
2021
·
IF 4.476
Lin Bo,Yongpeng Wang,Wenying Wang,Lei Wang,Fujin Li,Min Zuo,Yanzhen Ma,Degang Zhao
The ternary Cu 3 SbSe 4 thermoelectric material with diamond-like structure exhibit good thermoelectric performance in the middle temperature region. In this study, the Cu 3− x Ni x SbSe 4 ( x = 0–0.03) materials were fabricated by melting-ball milling-hot pressing process. The influences of grain size and compositional gradient on the microstructure and thermoelectric properties of Cu 3− x Ni x SbSe 4 were evaluated. It is found that the electrical conductivity of Cu 2.97 Ni 0.03 SbSe 4 was about 33% higher than that of Cu 3 SbSe 4 sample, and the lattice thermal conductivity was reduced from 3.3 Wm −1 K −1 to 2.4 Wm −1 K −1 at room temperature due to the grain refinement and more V Se defects. The maximum zT value for the Cu 2.97 Ni 0.03 SbSe 4 sample was 0.62 at 650 K.
研究领域:
材料科学
·
凝聚态物理
·
功能材料
·
热电材料
·
半导体材料
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry C
·
2018
·
IF 4.484
Jialun Tang,Sheng Huang,Zhaohan Li,Huaibin Shen,Zhao Lv,Haizheng Zhong
In this work, we reported the morphology evolution (formation of voids & size reduction) of gradient-alloyed CdxZn1–xSeyS1–y@ZnS quantum dots under electron irradiation during transmission electron microscopy observation. By investigating the correlations between shell gradients and morphology evolution, the formation of voids can be explained by the continuous electron irradiation-induced atomic movement under interfacial strain. On the other hand, the size reduction can be attributed to the elastic scattering-enabled sputtering of surface atoms. The as-formed voids of CdxZn1–xSeyS1–y@ZnS quantum dots with CdS-rich cores are much larger than those of ZnSe-rich ones, and the sizes of voids decreased with the increasing of shell thickness. The comparison of the morphology evolution of CdxZn1–xSeyS1–y@ZnS core–shell quantum dots with different composition gradients demonstrated that the size and shape of as-formed voids illustrate the strain characteristics of shell gradient. This provides a guideline to understand the strain effects in gradient-alloyed core–shell quantum dots through transmission electron microscopy measurement. We believe the deep insights into gradient-alloyed CdxZn1–xSeyS1–y@ZnS core–shell quantum dots would push forward their optimization toward commercialized light-emitting technology.
研究领域:
材料科学
·
纳米技术
·
物理学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Jialong Duan,Chenlong Zhang,Yueji Liu,Qiaoyu Zhang,Jie Dou,Qiyao Guo,Xiya Yang,Qunwei Tang
Electron cloud density around the functional group of Lewis-base molecule (passivator) highly determines the interaction strength with undercoordinated Pb 2+ in perovskite film. With the aim to maximize this scenario, herein, we fabricate a thermally-activated delayed fluorescence molecule (3,4,5,6-tetrakis(3,6-diphenylcarbazol-9-yl)-1,2-dicyanobenzene, 4CzPN-Ph) bound CsPbBr 3 nanocrystal (NC) to heal the defective perovskite surface. Because of the suitable energy alignment, there is a Förster or Dexter triplet energy transfer process from CsPbBr 3 NC donor to 4CzPN-Ph acceptor under light irradiation, leading to the increased electron density within 4CzPN-Ph molecule and thus the enhanced passivation ability. Together with the formation of compositional gradient layer owing to the halide exchange reaction with CsPbBr 3 NCs, the stable perovskite film with reduced defect is obtained, consequently promoting the efficiency up to 11.60 % for CsPbIBr 2 and 14.44 % for CsPbI 2 Br carbon-based devices, with excellent durability under harsh conditions.
研究领域:
材料科学
·
纳米技术
·
太阳能
·
光伏技术
·
半导体物理
✓ 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）