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1,972 results on '"Hou, Xun"'

5. Impermeable Inorganic Walls Sandwiching Photoactive Layer toward Inverted Perovskite Solar and Indoor-Photovoltaic Devices

Author

Xu, Jie, Xi, Jun, Dong, Hua, Ahn, Namyoung, Zhu, Zonglong, Chen, Jinbo, Li, Peizhou, zhu, Xinyi, Dai, Jinfei, Hu, Ziyang, Jiao, Bo, Hou, Xun, Li, Jingrui, and Wu, Zhaoxin

Subjects
Condensed Matter - Materials Science, Physics - Optics
Abstract

Interfaces between the perovskite active layer and the charge-transport layers (CTLs) play a critical role in both efficiency and stability of halide-perovskite photovoltaics. One of the major concerns is that surface defects of perovskite could cause detrimental nonradiative recombination and material degradation. In this work, we addressed this challenging problem by inserting ultrathin alkali-fluoride (AF) films between the tri-cation lead-iodide perovskite layer and both CTLs. This bilateral inorganic walls strategy makes use of both physical-blocking and chemical-anchoring functionalities of the continuous, uniform and compact AF framework: on the one hand, the uniformly distributed alkali-iodine coordination at the perovskite-AF interfaces effectively suppresses the formation of iodine-vacancy defects at the surfaces and grain boundaries of the whole perovskite film, thus reducing the trap-assisted recombination at the perovskite-CTL interfaces and therewith the open-voltage loss; on the other hand, the impermeable AF buffer layers effectively prevent the bidirectional ion migration at the perovskite-CTLs interfaces even under harsh working conditions. As a result, a power-conversion efficiency (PCE) of 22.02% (certified efficiency 20.4%) with low open-voltage deficit (< 0.4V) was achieved for the low-temperature processed inverted planar perovskite solar cells. Exceptional operational stability (500 h, ISOS-L-2) and thermal stability (1000 h, ISOS-D-2) were obtained. Meanwhile, a 35.7% PCE was obtained under dim-light source (1000 lux white LED light) with the optimized device, which is among the best records in perovskite indoor photovoltaics.

Published
2020

12. Energy transfer enhanced photoluminescence of 2D/3D CsPbBr3 hybrid assemblies.

Author

Wang, Chenxu, Si, Jinhai, Yan, Lihe, Li, Ting, and Hou, Xun

Subjects
ENERGY transfer, HOT carriers, PHOTOLUMINESCENCE
Abstract

Energy transfer has been proven to be an effective method to optimize optoelectronic conversion efficiency by improving light absorption and mitigating nonradiative losses. We prepared 2D/3D CsPbBr3 hybrid assemblies at different reaction temperatures using the hot injection method and found that the photoluminescence quantum yields (PLQYs) of these hybrids were greatly enhanced from 53.4% to 72.57% compared with 3D nanocrystals (NCs). Femtosecond transient absorption measurements were used to study the PLQY enhancement mechanisms, and it was found that the hot carrier lifetime improved from 0.36 to 1.88 ps for 2D/3D CsPbBr3 hybrid assemblies owing to the energy transfer from 2D nanoplates to 3D NCs. The energy transfer benefits the excited carrier accumulation and prolonged hot carrier lifetime in 3D NCs in hybrid assemblies, as well as PLQY enhancement in materials. [ABSTRACT FROM AUTHOR]

Published
2024
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13. Ultrafast photoinduced carrier transfer dynamics in monolayer MoS2/graphene heterostructure.

Author

Liu, Ben, Yan, Lihe, Si, Jinhai, Shen, Yanan, and Hou, Xun

Subjects
MONOMOLECULAR films, HOT carriers, MOLYBDENUM disulfide, PHOTOEXCITATION, AUTOMATIC timers, EXCITON theory, GRAPHENE, PHOTODETECTORS
Abstract

Two-dimensional molybdenum disulfide (MoS2) has been proved to be a good candidate in photodetectors, and MoS2/graphene (MoS2/G) heterostructure has been widely used to expand the optical response wavelength of MoS2. To clarify the carrier transfer dynamics in the MoS2/G heterostructure, time-resolved transient absorption and two-color pump–probe measurements are performed. By comparing the carrier dynamics in MoS2 and MoS2/G under different pump wavelengths, we find that interfacial excitons are formed in the heterostructure, and fast hot carriers transfer (<200 fs) from graphene to MoS2 are observed. The results indicate that the formed heterostructure with graphene can not only expand the optical response wavelength of MoS2 but also improve the response time of the device in the near-infrared region. [ABSTRACT FROM AUTHOR]

Published
2023
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32. Femtosecond Laser Fabrication of High-Linearity Liquid Metal-Based Flexible Strain Sensor.

Author

Li, Cheng, Zhang, Chengjun, Li, Haoyu, Luo, Zexiang, Zhang, Yuanchen, Hou, Xun, Yang, Qing, and Chen, Feng

Subjects
STRAIN sensors, FEMTOSECOND lasers, ELECTRONIC equipment, LIQUID metals, ELECTRODE performance, LIQUIDS
Abstract

Liquid metal (LM) is widely used in flexible electronic devices due to its excellent metallic conductivity and ductility. However, the fabrication of LM flexible strain sensors with high sensitivity and linearity is still a huge challenge, since the resistance of LM does not change much with strain. Here, a highly sensitive and linear fully flexible strain sensor with a resistive sensing function is proposed. The sensor comprises an Fe-doped liquid metal (Fe-LM) electrode for enhanced performance. The design and manufacturing of flexible strain sensors are based on the technology of controlling surface wettability by femtosecond laser micro/nano-processing. A supermetalphobic microstructure is constructed on a polydimethylsiloxane (PDMS) substrate to achieve the selection adhesion of Fe-LM on the PDMS substrate. The Fe-LM-based flexible strain sensor has high sensitivity and linearity, a gauge factor (GF) up to 1.18 in the strain range of 0–100%, excellent linearity with an R2 of 0.9978, a fast response time of 358 ms, and an excellent durability of more than 2400 load cycles. Additionally, the successful monitoring of human body signals demonstrates the potential of our developed flexible strain sensor in wearable monitoring applications. [ABSTRACT FROM AUTHOR]

Published
2024
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