强激光与粒子束
2024, 36(1): 013006
Author Affiliations
Abstract
1 North China Electric Power University and Hebei Key Laboratory of Physics and Energy Technology, Beijing 102206, China
2 School of Integrated Circuits & Beijing National Research on Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
Two-dimensional (2D) WSe2 has received increasing attention due to its unique optical properties and bipolar behavior. Several WSe2-based heterojunctions exhibit bidirectional rectification characteristics, but most devices have a lower rectification ratio. In this work, the Bi2O2Se/WSe2 heterojunction prepared by us has a type Ⅱ band alignment, which can vastly suppress the channel current through the interface barrier so that the Bi2O2Se/WSe2 heterojunction device has a large rectification ratio of about 105. Meanwhile, under different gate voltage modulation, the current on/off ratio of the device changes by nearly five orders of magnitude, and the maximum current on/off ratio is expected to be achieved 106. The photocurrent measurement reveals the behavior of recombination and space charge confinement, further verifying the bidirectional rectification behavior of heterojunctions, and it also exhibits excellent performance in light response. In the future, Bi2O2Se/WSe2 heterojunction field-effect transistors have great potential to reduce the volume of integrated circuits as a bidirectional controlled switching device.
Bi2O2Se WSe2 heterojunction bidirectional rectification optoelectronic devices Journal of Semiconductors
2024, 45(1): 012701
南京工业大学数理科学学院，江苏 南京 211816
本文使用同轴静电纺丝技术，以合适的钒源和锡源为前驱体，在不同的热处理条件下，制备V2O5/SnO2纳米纤维异质结构，并构筑高灵敏的光电探测器件。在偏置电压为2.0 V、波长为405 nm的激光辐照下，V2O5/SnO2纳米纤维异质结构显示出1.28 μA的光电流，相比纯V2O5纳米纤维光电探测器（0.43 μA），光电流提高了近三倍。在偏置电压为3.0 V的周期性激光的调制下，V2O5/SnO2纳米纤维异质结光电探测器表现出快速的光响应，响应和衰减时间均为0.566 s，响应度为3.97 A/W，比探测率为 Jones，表现出良好的光电探测性能。这些实验结果为V2O5/SnO2纳米纤维异质结构在光电子器件中的应用提供了新的思路。
V2O5 V2O5/SnO2纳米纤维异质结 静电纺丝 光电探测器
1 1.内蒙古科技大学 材料与冶金学院, 包头 014010
2 2.稀土资源绿色提取与高效利用教育部重点实验室, 包头 014010
制备高效稳定的光催化剂对于光催化技术的发展至关重要。本研究采用超声辅助沉积加低温煅烧的方法制备了2H相MoS2/g-C3N4 S型异质结光催化剂(MGCD), 并综合考察了材料的相结构、微观形貌、光吸收性能、X射线光电子能谱、电化学交流阻抗和光电流等对光催化性能的影响。结果表明: 经过超声辅助沉积-煅烧处理, MoS2微米球发生破碎分散结合在g-C3N4纳米片层表面上并形成异质结。可见光下5%MGCD(添加5% MoS2)对罗丹明B(RhB)在20 min时的降解率达到了99%, 且样品重复使用5次后对RhB的降解率仍能达到95.2%, 表现出良好的光催化性能及稳定性。从内建电场形成的角度进一步分析表明, 异质结中MoS2与g-C3N4间耦合形成的内建电场引起的能带弯曲可以有效引导载流子的定向迁移, 并促进光生载流子的分离, 从而提高了光催化反应效率。异质结光催化剂的自由基捕获实验表明: O2-和·OH在催化降解RhB中是主要的活性物种, h+的贡献次之。
石墨相氮化碳 MoS2 S型异质结 稳定性 光催化机理 g-C3N4 MoS2 S-type heterojunction stability photocatalytic mechanism
Author Affiliations
Abstract
School of Materials Science and Engineering, Xiangtan University, Hunan, Xiangtan 411105, P. R. China
Two-dimensional -In2Se3 exhibits simultaneous intercorrelated in-plane and out-of-plane polarization, making it a highly promising material for use in memories, synapses, sensors, detectors, and optoelectronic devices. With its narrow bandgap, -In2Se3 is particularly attractive for applications in photodetection. However, relatively little research has been conducted on the out-of-plane photoconductive and bulk photovoltaic effects in -In2Se3. This limits the potential of -In2Se3 in the device innovation and performance modification. Herein, we have developed an -In2Se3-based heterojunction with a transparent electrode of two-dimensional Ta2NiS5. The out-of-plane electric field can effectively separate the photo-generated electron–hole pairs in the heterojunction, resulting in an out-of-plane responsivity (R), external quantum efficiency (EQE), and specific detectivity () of 0.78mA/W, 10% and Jones, respectively. The out-of-plane bulk photovoltaic effect has been demonstrated by changes in the short circuit current (SCC) and open circuit voltage () with different optical power intensity and temperature, which indicates that -In2Se3-based heterojunctions has application potential in mid-far infrared light detection based on its out-of-plane photoconductive and bulk photovoltaic effects. Although the out-of-plane photoconductive and bulk photovoltaic effects are relatively lower than that of traditional materials, the findings pave the way for a better understanding of the out-of-plane characteristics of two-dimensional -In2Se3 and related heterojunctions. Furthermore, the results highlight the application potential of -In2Se3 in low-power device innovation and performance modification.
Photoconductive effect bulk photovoltaic effect ferroelectric heterojunction Journal of Advanced Dielectrics
2023, 13(6): 2345001
白城师范学院 纳米光催化材料研究中心, 白城 137000
光催化CO2还原技术的关键是开发高效光催化剂, 而构建具有紧密界面结构的异质结是增强界面电荷转移, 实现高效光催化活性的有效途径。本研究采用静电纺丝技术结合水热法, 将Bi4O5Br2纳米片镶嵌在CeO2纳米纤维表面, 制得Bi4O5Br2/CeO2纤维光催化材料(B@C-x, x对应反应物的加入量)。利用不同方法表征其微观结构、形貌和光电性能。结果表明, 适当Bi4O5Br2含量的Bi4O5Br2/CeO2异质结可以显著提高CeO2纳米纤维的光催化性能。与纯Bi4O5Br2和CeO2相比, B@C-2在模拟太阳光下表现出最佳光催化活性, 不使用任何牺牲剂或共催化剂的条件下, CO生成速率达到8.26 μmol·h−1·g−1。这归因于Bi4O5Br2和CeO2之间的界面结合紧密以及构建的S型异质结, 使得光生载流子可以实现有效的空间分离和转移。本研究为定向合成Bi基S型异质结复合光催化材料提供了一种简便有效的方法, 为清洁能源转换探索了可行的途径。
Bi4O5Br2/CeO2复合纤维 异质结 光催化CO2还原 水热法 Bi4O5Br2/CeO2 composite fiber heterojunction photocatalytic CO2 reduction hydrothermal method 
