Article
Chemistry, Physical
Yun Xia Zhang, Yuan He, Yi Liang, Jie Tang, Yang Yang, He Ming Song, Miklos Zrinyi, Yong Mei Chen
Summary: A piezoresistive pressure sensor was prepared by decorating pyramid microarrays on the surface of a tough and ionically conductive PAAm/PVA hydrogel. The sizes and topologies of the recessed pyramid microarrays were investigated for elaborate fabrication. The decorated hydrogel showed large contact resistance variation in response to external pressure, achieving high sensitivity, low detection limit, and good recoverability and stability.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Hehe Zhang, Jan Mischke, Wolfgang Mertin, Gerd Bacher
Summary: This paper provides an overview of the current status of graphene-based transparent conductive electrodes in GaN-based LEDs. It focuses on manufacturing progress and the resulting properties of the fabricated devices, discussing the impact of graphene-based transparent conductive electrodes on current spreading and contact resistance, as well as future challenges and perspectives on the use of graphene in GaN-based LEDs.
Article
Nanoscience & Nanotechnology
Sriharsha Sudhindra, Farnia Rashvand, Dylan Wright, Zahra Barani, Aleksey D. Drozdov, Saba Baraghani, Claudia Backes, Fariborz Kargar, Alexander A. Balandin
Summary: The study revealed that increasing the size of graphene fillers enhances the thermal conductivity of composites, with fillers of 1200 nm lateral dimensions exhibiting lower thermal contact resistance. The effects of filler loading fraction and size on thermal conductivity were rationalized using the Kanari model. These findings are crucial for optimizing graphene fillers in thermal interface materials for efficient heat removal in high-power-density electronics.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Engineering, Electrical & Electronic
Amit Kumar, Himanshu Singh, Shubham Sahay, Krishna B. Balasubramanian
Summary: In this study, the charge transport efficiency between Cu2O thin films and commonly used metallic stack contact materials was systematically investigated. The results showed that a Ti-Au metal combination achieved the lowest contact resistivity on Cu2O thin films.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Chemistry, Multidisciplinary
Sami Ramadan, Yuanzhou Zhang, Deana Kwong Hong Tsang, Olena Shaforost, Lizhou Xu, Ryan Bower, Iain E. Dunlop, Peter K. Petrov, Norbert Klein
Summary: The performance of graphene devices can be limited by defects and impurities introduced during fabrication, but using HMDS as a buffer layer during device fabrication can significantly reduce damage, improve graphene quality, and enhance device performance.
Article
Chemistry, Physical
Arthur Triana, Jhon J. Olaya, C. Prieto
Summary: The corrosion resistance of a single-layer graphene film synthesized through chemical vapor deposition (CVD) on a polycrystalline copper substrate was investigated. The study examined the film's ability to resist corrosion in different electrolyte environments and discussed the corrosion mechanism and degradation level of the graphene.
SURFACES AND INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Hyunmin Cho, Donghee Kang, Yangjin Lee, Heesun Bae, Sungjae Hong, Yongjae Cho, Kwanpyo Kim, Yeonjin Yi, Ji Hoon Park, Seongil Im
Summary: In addressing the high contact resistance in 2D devices, the use of thermal-evaporated ultrathin LiF between channel and source/drain metal has shown promising results in reducing RC values in MoS2 FETs. By utilizing the 4-bar FET method, lower RC values can be achieved, while transparent conducting oxide contact enables transparent MoS2 FETs to be realized.
Article
Thermodynamics
Jiawei Yang, Wei Yu, Yuan Zhang, Changqing Liu, Huaqing Xie
Summary: The article introduces a novel thermal interface material obtained by incorporating graphene into a polyacrylate-based double cross-linked hydrogel, which exhibits low thermal contact resistance, high thermal conductivity, excellent elasticity, and self-healing properties, meeting the requirements of a dynamic working environment. The study found that under certain pressure, the effect of temperature on thermal contact resistance is minor, indicating the excellent thermal management performance of the composite hydrogel.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Materials Science, Composites
Xue Tan, Junfeng Ying, Jingyao Gao, Qingwei Yan, Le Lv, Kazuhito Nishimura, Qiuping Wei, He Li, Shiyu Du, Bin Wu, Rong Xiang, Jinhong Yu, Nan Jiang, Cheng-Te Lin, Wen Dai
Summary: This study addresses the challenge of achieving high through-plane thermal conductivity and low contact thermal resistance for thermal interface materials (TIMs) by constructing a loosely packed and vertically aligned graphene monolith. A cap modification strategy with nanometer-thick gold foils was carried out to optimize the contact state, resulting in a significant enhancement in cooling efficiency compared to state-of-the-art TIMs, showcasing the superior ability of the proposed graphene-based TIM to meet increasing heat dissipation requirements.
COMPOSITES COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Niloofar Majidian Taleghani, Zahra Heydari, Mahdi Madani, Aryanaz Faghih Nasiri, Mohammadreza Kolahdouz, Hamed Abdy
Summary: This study improves the processing and electrical performance of CuSCN by using suitable solvents and co-solvents, choosing the proper back contact metal, and adding substitution additives.
Article
Energy & Fuels
M. Ignacia Devoto, Karl Wienands, Dominik Rudolph, Tudor Timofte, Andreas Halm, Ralph Gottschalg, Daniel Tune
Summary: Accurate determination of contact resistivity between ECAs and solar metallization paste is crucial for optimizing ECA-based bonds. This study proposed and validated a methodology that takes into account the non-uniformity of test structures based on ECAs and silver screen-printed metallization, improving the accuracy of contact resistivity calculations. Statistical analysis showed that bonds based on commercially available ECAs could be clearly differentiated with high confidence and low error margin. The necessary sample size for such distinction was calculated to be 24 test structures. This methodology is expected to be useful for developers and researchers in improving and optimizing ECAs and ECA bonding processes.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2023)
Article
Energy & Fuels
M. Ignacia Devoto Acevedo, Stephan Grosser, Karl Wienands, Tudor Timofte, Andreas Halm, Ralph Gottschalg, Daniel Tune
Summary: The contact resistivity plays a significant role in the performance of solar module interconnects. However, accurately measuring the contact resistivity for interconnects based on electrically conductive adhesive (ECA) is challenging. This study demonstrates that transmission line method (TLM) test structures based on ECA exhibit non-negligible inhomogeneities, leading to inaccuracies in determining the contact resistivity. The analysis of four commercially available ECAs used in solar modules reveals that even without macroscale inhomogeneities, microscopic structural effects affect the sheet and contact resistance, particularly due to variations in filler distribution.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2023)
Article
Engineering, Electrical & Electronic
Honghwi Park, Junyeong Lee, Chang-Ju Lee, Jaeeuk Kim, Jaewoon Kang, Hyowoong Noh, Jonghyung Lee, Youngjin Park, Jonghoo Park, Muhan Choi, Hongsik Park
Summary: Graphene grown by CVD is polycrystalline and its performance is dependent on grain size. The sheet resistance of graphene is related to device dimensions, allowing for precise evaluation of average grain size using an electrical method.
SOLID-STATE ELECTRONICS
(2021)
Article
Nanoscience & Nanotechnology
Niming Peng, Lanlan Wang, Wei Jiang, Guojun Li, Bangdao Chen, Weitao Jiang, Hongzhong Liu
Summary: This study presents a novel method for designing and fabricating T-shaped micropyramid structures with excellent waterproofing. By optimizing the inherent microstructures, the integration of waterproofing and sensing is achieved. Experimental results demonstrate that the structures exhibit good waterproofing performance underwater, opening up new possibilities for flexible sensing interfaces.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Textiles
Xinghua Hong, Rufang Yu, Yubing Dong, Junmin Wan, Hongxia Zhang, Chengyan Zhu
Summary: The study focused on the resistance temperature-sensitive behavior and interfacial electricity of reduced graphene oxide/polyester fabric, demonstrating promising potential in the field of wearable electric heaters. The fabric exhibited temperature sensitivity and achieved an equilibrium temperature of 89 degrees C in 20 seconds. Investigating the contact resistance at the interface provided a qualitative decoupling analysis method for the study of interfacial electricity and electrothermal distribution.
JOURNAL OF INDUSTRIAL TEXTILES
(2022)
Article
Engineering, Electrical & Electronic
Sergey A. Blokhin, Andrey Babichev, Andrey G. Gladyshev, Leonid Ya Karachinsky, Innokenty I. Novikov, Alexey A. Blokhin, Mikhail A. Bobrov, Nikolay A. Maleev, Vladislav V. Andryushkin, Dmitrii Denisov, Kirill O. Voropaev, Irina O. Zhumaeva, Victor M. Ustinov, Anton Yu Egorov, Nikolay N. Ledentsov
Summary: High power single mode wafer-fused 1300-nm VCSELs with a gain region based on InGaAs/InAlGaAs short period superlattice were fabricated. The VCSELs demonstrated high output power, modulation bandwidth, low threshold current, and low internal optical losses.
IEEE JOURNAL OF QUANTUM ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
E. D. Cherotchenko, V. V. Dudelev, D. A. Mikhailov, S. N. Losev, A. Babichev, A. G. Gladyshev, I. I. Novikov, A. Lutetskiy, D. A. Veselov, S. O. Slipchenko, N. A. Pikhtin, L. Ya Karachinsky, D. Denisov, V. Kuchinskii, E. A. Kognovitskaya, A. Yu Egorov, R. Teissier, A. N. Baranov, G. S. Sokolovskii
Summary: We experimentally studied the turn-on delay in pulsed mid-infrared quantum cascade lasers. We observed unexpected long delay time depending on the pumping current, which contradicts conventional theoretical predictions for step-like excitation. Similar behavior was also observed in InP and InAs-based QCLs emitting near 8 um. Numerical simulations using a model based on rate equations with non-zero rise time for excitation by current pulses provided a good agreement with our observations.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Crystallography
Elena Balashova, Aleksandr A. Levin, Valery Davydov, Alexander Smirnov, Anatoly Starukhin, Sergey Pavlov, Boris Krichevtsov, Andrey Zolotarev, Hongjun Zhang, Fangzhe Li, Hua Ke
Summary: The study on glycine single crystals doped with croconic acid reveals that doping with croconic acid causes changes in the optical properties of glycine crystals, including bandgap and absorption spectra, and leads to strong green photoluminescence.
Article
Nanoscience & Nanotechnology
Thejas Kurunthatil Kuttiat, Malini Abraham, Arup K. Kunti, Nuno Amador-Mendez, Maria Tchernycheva, Subrata Das
Summary: Modifying Mn4+-containing oxides has led to the development of new materials with strong deep-red emission, which can be used in high color rendering and cost-effective white-light emitting diodes (WLEDs).
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Engineering, Electrical & Electronic
Andrey Babichev, Sergey Blokhin, Andrey Gladyshev, Leonid Karachinsky, Innokenty Novikov, Alexey Blokhin, Mikhail Bobrov, Nikolay Maleev, Vladislav Andryushkin, Evgenii Kolodeznyi, Dmitrii Denisov, Natalia Kryzhanovskaya, Kirill Voropaev, Victor Ustinov, Anton Egorov, Hui Li, Si-Cong Tian, Saiyi Han, Georgiy Sapunov, Dieter Bimberg
Summary: High power single-mode wafer fused 1550 nm VCSELs with InGaAs quantum wells and InP-based optical cavity, along with AlGaAs/GaAs distributed Bragg reflector heterostructures were fabricated. The VCSELs demonstrated a single-mode continuous wave output optical power of approximately 3.4 mW and a threshold current of about 2 mA at 20 degrees C. The output optical power exceeded 1 mW at 70 degrees C, and a -3dB modulation bandwidth of > 13 GHz was obtained at 20 degrees C. Non-return-to-zero data transmission at a speed of approximately 37 Gbps was achieved under back-to-back conditions.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2023)
Article
Chemistry, Physical
Kirill V. Bogdanov, Ilya E. Kaliya, Mikhail A. Baranov, Sergey A. Grudinkin, Nikolay A. Feoktistov, Valery G. Golubev, Valery Yu. Davydov, Alexander N. Smirnov, Alexander V. Baranov
Summary: This study reports a preparation method of a multi-color light source based on nanodiamonds, which achieves multi-frequency emission by introducing luminescent color centers and tungsten complexes in the diamond matrix. The results show that the nanodiamond matrix has good luminescent properties and electron-phonon interaction.
Article
Nanoscience & Nanotechnology
Laurent Boulley, Thomas Maroutian, Paul Goulain, Andrey Babichev, Anton Egorov, Lianhe Li, Edmund Linfield, Raffaele Colombelli, Adel Bousseksou
Summary: We demonstrate low temperature deposition conditions for VO2 phase change material that are compatible with III-V semiconductors used in optoelectronic applications. The VO2 coated thin films grown on GaAs exhibit a 50% change in optical reflectivity and a significant variation in electric conductivity between insulating and metallic states. We also study the functionalization of mid-infrared QCLs with VO2 layers to engineer their laser emission properties.
Article
Chemistry, Physical
Elena Balashova, Andrey Zolotarev, Aleksandr A. A. Levin, Valery Davydov, Sergey Pavlov, Alexander Smirnov, Anatoly Starukhin, Boris Krichevtsov, Hongjun Zhang, Fangzhe Li, Huijiadai Luo, Hua Ke
Summary: Single crystals of 2-methylbenzimidazolium perchlorate were prepared for the first time by slow evaporation method from an aqueous solution. The crystal structure was determined by XRD and confirmed by powder XRD. The crystals exhibited molecular and lattice vibrations in the Raman and FTIR spectra, and a protonation of MBI molecule in the crystal was observed. The optical gap of the crystals was estimated to be approximately 3.9 eV based on UV-Vis absorption spectra. The crystals also showed photoluminescence with a main maximum at approximately 2.0 eV. The crystals exhibited two first-order phase transitions with different temperature hysteresis, accompanied by an increase in permittivity and conductivity, resembling the effect of an ionic liquid.
Article
Materials Science, Multidisciplinary
Ilya A. A. Eliseyev, Bogdan R. R. Borodin, Dmitrii R. R. Kazanov, Alexander V. V. Poshakinskiy, Maja Remskar, Sergey I. I. Pavlov, Lyubov V. V. Kotova, Prokhor A. A. Alekseev, Alexey V. V. Platonov, Valery Yu. Davydov, Tatiana V. V. Shubina
Summary: Synthesized micro- and nanotubes composed of TMDCs like MoS2 show potential for applications in nanophotonics due to their strong exciton luminescence and ability to act as whispering gallery microcavities at room temperature. The study focuses on a class of twisted tubes with a flattened cross-section that rotates along the tube axis. The results show the possibility of creating multifunctional tubular TMDC nanodevices that can amplify self-emitting light at adjustable frequencies.
ADVANCED OPTICAL MATERIALS
(2023)
Review
Optics
Andrey Babichev, Sergey Blokhin, Evgenii Kolodeznyi, Leonid Karachinsky, Innokenty Novikov, Anton Egorov, Si-Cong Tian, Dieter Bimberg
Summary: Single-mode long-wavelength vertical-cavity surface-emitting lasers (VCSELs) are a cost-effective alternative to DFB-lasers for data communication in next-generation giga data centers. Spatial division multiplexing transmission through multicore fibers using these lasers allows for larger-scale data center networks. Achieving high-speed modulation is discussed in this review, including the state-of-the-art technology and the use of hybrid short-cavity concept and wafer-fusion concepts.
Article
Optics
Andrey Babichev, Sergey Blokhin, Andrey Gladyshev, Leonid Karachinsky, Innokenty Novikov, Alexey Blokhin, Mikhail Bobrov, Yakov Kovach, Alexander Kuzmenkov, Vladimir Nevedomsky, Nikolay Maleev, Evgenii Kolodeznyi, Kirill Voropaev, Alexey Vasilyev, Victor Ustinov, Anton Egorov, Saiyi Han, Si-Cong Tian, Dieter Bimberg
Summary: A detailed experimental analysis on the impact of device topology on the performance of 1550 nm VCSELs is presented. The high-speed performance of the lasers with L-type device topology is mainly limited by electrical parasitics, while the S-type device topology allows for higher parasitic cutoff frequency and demonstrates more than 13 GHz modulation bandwidth and up to 37 Gbps data transmission under back-to-back conditions at 20°C.
Article
Nanoscience & Nanotechnology
Bogdan R. Borodin, Fedor A. Benimetskiy, Valery Yu. Davydov, Ilya A. Eliseyev, Prokhor A. Alekseev
Summary: Van der Waals (vdW) heterostructures are promising for next-generation two-dimensional electronic and optoelectronic devices. However, obtaining an ideal interface is still challenging due to a lack of contamination-free fabrication techniques. This study investigates the effect of interfacial conditions on the optical and electronic properties of a MoSe2/Au heterostructure, revealing that interfacial contamination severely affects its electronic and optical properties. The results of this work are important for the fabrication of vdW devices.
ACS APPLIED NANO MATERIALS
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
P. Dalapati, E. M. Weikum, G. Beainy, E. Di Russo, J. Houard, S. Moldovan, A. Vella, J. M. Chauveau, M. Hugues, N. Le Biavan, M. Tchernycheva, F. H. Julien, Z. Saghi, L. Rigutti
Summary: In this study, we investigated the polarization properties of photoluminescence emitted from a ZnO-(Mg, Zn)O quantum well heterostructure embedded within an atom probe tip. We found that the luminescence from bulk ZnO and (Mg, Zn)O alloy is strongly polarized along the crystal [1-100] axis, while the luminescence from the ZnO/(Mg, Zn)O quantum well is strongly polarized in its in-plane direction, perpendicular to the crystal [1-100] axis.
OXIDE-BASED MATERIALS AND DEVICES XIII
(2022)
