Article
Nanoscience & Nanotechnology
Cihyun Kim, Tae Jin Yoo, Min Gyu Kwon, Kyoung Eun Chang, Hyeon Jun Hwang, Byoung Hun Lee
Summary: The structure of a gate-controlled graphene/germanium hybrid photodetector was optimized by splitting the active region, resulting in significantly improved infrared detection capability.
Article
Nanoscience & Nanotechnology
Cihyun Kim, Tae Jin Yoo, Kyoung Eun Chang, Min Gyu Kwon, Hyeon Jun Hwang, Byoung Hun Lee
Summary: The performance of a graphene/Ge Schottky junction near-infrared photodetector is significantly enhanced by inserting a thin Al2O3 interfacial layer between graphene and Ge. Dark current is reduced by two orders of magnitudes, and the specific detectivity is improved to 1.9 x 10(10) cm . Hz(1/2)W(-1). The responsivity is improved to 1.2 AW(-1) with an interfacial layer from 0.5 AW(-1) of the reference devices. The normalized photo-todark current ratio is improved to 4.3 x 10(7) W-1 at a wavelength of 1550 nm, which is 10-100 times higher than those of other Ge photodetectors.
Article
Chemistry, Multidisciplinary
Hanyu Wang, Yan Li, Peng Gao, Jina Wang, Xuefeng Meng, Yin Hu, Juehan Yang, Zihao Huang, Wei Gao, Zhaoqiang Zheng, Zhongming Wei, Jingbo Li, Nengjie Huo
Summary: This study develops a photovoltaic detector with polarization- and gate-tunable optoelectronic reverse phenomenon, which can acquire higher resolution and more surface information of imaging targets by identifying the polarization of light. The device exhibits a wide range of current rectification ratio and clear object imaging, with a polarization ratio value of approximately 30, making significant progress in polarimetric imaging and multifunction integration applications.
ADVANCED MATERIALS
(2023)
Article
Optics
Hassan Sadeghi, Vahid Talebi, Hadi Soofi
Summary: In this article, a widely tunable graphene-liquid crystal photodetector is proposed and investigated. The photodetector utilizes a liquid crystal layer as a Fabry-Perot filter to achieve frequency selectivity, and operates based on internal photoemission from Si/graphene Schottky junction. The structure allows for wide tunability in the operation band and detection wavelength, making it suitable for optical communications. The article discusses the dependence of the photodetector characteristics on graphene fermi energy, liquid crystal voltage, and Si grating parameters.
OPTICS COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Yingcheng Qiu, Shan Zhang, Guanglin Zhang, Zhengyi He, Xiaoqiang Feng, Fei Ding, Shiwei Tang, Gang Wang
Summary: By growing a bottom 2D graphene directly on a Ge substrate and synthesizing a middle 3D graphene in-situ using 2D graphene as the buffer layer, and transferring a top 2D graphene to form a vertical 2D/3D/2D graphene sandwich structure on the Ge substrate, the light absorption and photodetection performance can be improved.
DIAMOND AND RELATED MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Ala K. Jehad, Mehmet Fidan, Ozhan Unverdi, Cem Celebi
Summary: A self-powered, high-performance graphene/Silicon Carbide ultraviolet photodetector was fabricated, and the effect of using monolayer and bilayer graphene on device performance parameters was investigated. The photodetector exhibited high spectral responsivity, maximum detectivity, and minimum noise equivalent power. Bilayer graphene showed no significant change in spectral responsivity but improved the response speed compared to monolayer graphene.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Materials Science, Multidisciplinary
Xiwei Zhang, Jiahua Shao, Chenxi Yan, Xinmiao Wang, Yufei Wang, Zhihui Lu, Ruijie Qin, Xiaowen Huang, Junlong Tian, Longhui Zeng
Summary: MXenes, as a novel family of 2D materials, show great potential in optoelectronic devices and systems. The Ti3C2Tx/GaAs Schottky junction photodetector demonstrates high sensitivity, good responsivity, and high specific detectivity, indicating promising applications in high performance broadband, self-driven photodetection.
MATERIALS & DESIGN
(2021)
Article
Optics
Zijing Wang, Xuegong Yu, Xiaodong Qiu, Jiawei Fu, Deren Yang
Summary: The use of graphene as the carrier transport layer in high-responsivity silver hyperdoped silicon heterostructure infrared photoconductors significantly improves the carrier separation and collection efficiency, leading to an external quantum efficiency of 97.26% at 1310 nm and 7.37% at 1550 nm under a low bias of 0.3 V. These results pave the way for hyperdoped silicon heterostructure infrared photodetectors with high responsivity.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Chemistry, Physical
Venkatarao Selamneni, Vivek Adepu, Harini Raghavan, Parikshit Sahatiya
Summary: This study investigated the use of Ti3C2TX (MXene) as a transport layer and 2D ReS2 as an active material to fabricate a broadband photodetector on paper substrate, compared with graphene. The results showed that MXene as a transport layer significantly enhances the detector performance and has potential applications in the future.
Article
Chemistry, Multidisciplinary
Cesar D. D. Mendoza, F. L. Freire Jr
Summary: We investigated the interfacial electronic structure of single-layer graphene on a germanium substrate using UPS and XPS. The graphene was directly synthesized on (110) undoped Ge substrate via CVD. The study identified the main graphitic properties and showed that the Ge substrate affected the electronic structure of the graphene due to electronic coupling. The study also provided important information on the Schottky contact's nature and energy level alignments for potential integration of single-layer graphene on a Ge substrate with CMOS technology.
Article
Materials Science, Multidisciplinary
Yuchen Zhou, Lixiang Han, Qiqi Song, Wei Gao, Mengmeng Yang, Zhaoqiang Zheng, Le Huang, Jiandong Yao, Jingbo Li
Summary: This study proposes a hybrid heterostructure photodetector composed of 1D Te and 2D WS2. The combination of these materials induces strain in WS2 and creates a vertical heterojunction, resulting in high sensitivity and anisotropic photodetection characteristics.
SCIENCE CHINA-MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Aniello Pelella, Alessandro Grillo, Enver Faella, Giuseppe Luongo, Mohammad Bagher Askari, Antonio Di Bartolomeo
Summary: The fabrication of a graphene-silicon junction involves the formation of a parallel metal-insulator-semiconductor (MIS) structure, which plays an important role in the optoelectronic properties of the device. The graphene-silicon device exhibits rectifying behavior and operates as a photodetector in both photocurrent and photovoltage mode in the visible and infrared spectral regions. The device's electrical behavior is explained by a model based on two parallel and opposite diodes.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Nanoscience & Nanotechnology
Hassan Algadi, Tanmoy Das, Junna Ren, Handong Li
Summary: A high-performance and stable hybrid photodetector based on a monolayer MoS2/NH2 GQDs/CsPbBr3 triple junction is developed. The introduction of NH2 GQDs enhances carrier transport, separation, and optical absorption in the triple junction. The hybrid photodetector exhibits superior performance compared to reported devices based on 2D materials, perovskite, and other heterostructures. The excellent alignment between MoS2, NH2 GQDs, and CsPbBr3 reduces recombination and increases photon-absorption rate, leading to enhanced performance.
ADVANCED COMPOSITES AND HYBRID MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Yance Chen, Xiaoxue Cao, Suhao Wang, Lixiang Liu, Jianhang Lv, Xinyu Liu, Srikrishna Chanakya Bodepudi, Ying Shen, Haiyan Sun, Li Peng, Wenzhang Fang, Jizhou Song, Yang Xu
Summary: In this study, a p-type silicon/graphene/n-type silicon heterojunction was used to fabricate a near-infrared photodetector, and dual built-in electric fields were established in the same direction to enhance electron-hole separation. The resulting device showed higher responsivities and external quantum efficiency compared to the single-junction heterojunction device.
IEEE TRANSACTIONS ON NANOTECHNOLOGY
(2022)
Article
Chemistry, Analytical
Xiyuan Dai, Li Wu, Kaixin Liu, Fengyang Ma, Yanru Yang, Liang Yu, Jian Sun, Ming Lu
Summary: We propose a straightforward approach to develop a high-detectivity silicon sub-bandgap near-infrared photodetector using textured Si/Au nanoparticle Schottky junctions coated with a graphene film. The photodetector operates at 0 V bias and achieves enhanced NIR absorption through the texturing of Si and sub-bandgap absorption through Schottky junctions. The use of graphene further increases photocurrent through additional pathways for hot electron transport. The developed photodetector demonstrates a responsivity of 3.9 mA/W and a detectivity of 7.2 x 10(10) cm x (Hz)(1/2)/W under 1319 nm illumination at room temperature.
Article
Materials Science, Multidisciplinary
Tae Hyeon Kim, Woojin Park, Seyoung Oh, So-Young Kim, Naohito Yamada, Hikaru Kobayashi, Hye Yeon Jang, Jae Hyeon Nam, Hiroki Habazaki, Byoung Hun Lee, Byungjin Cho
Summary: Inserting an Al2O3 interlayer between metal electrodes and a semiconducting channel improves transistor performance and gate bias stress stability, attributed to a doping effect and mitigation of interface defects. Energy-band diagrams obtained experimentally validate the channel doping effect, increasing tunneling probability of charge carriers. Comprehensive study on processing parameters guides practical implementation of stable sol-gel oxide-based thin-film transistors for integrated circuitry applications.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2021)
Article
Engineering, Electrical & Electronic
Jun-Young Park, Tae Jin Yoo, Ji-Man Yu, Byoung Hun Lee, Yang-Kyu Choi
Summary: This work experimentally confirmed the relationship between passivation gas species and curing characteristics during transistor-level annealing, and it was found that the existence of deuterium in a device was strongly associated with curing behavior.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Nanoscience & Nanotechnology
Cihyun Kim, Tae Jin Yoo, Kyoung Eun Chang, Min Gyu Kwon, Hyeon Jun Hwang, Byoung Hun Lee
Summary: The performance of a graphene/Ge Schottky junction near-infrared photodetector is significantly enhanced by inserting a thin Al2O3 interfacial layer between graphene and Ge. Dark current is reduced by two orders of magnitudes, and the specific detectivity is improved to 1.9 x 10(10) cm . Hz(1/2)W(-1). The responsivity is improved to 1.2 AW(-1) with an interfacial layer from 0.5 AW(-1) of the reference devices. The normalized photo-todark current ratio is improved to 4.3 x 10(7) W-1 at a wavelength of 1550 nm, which is 10-100 times higher than those of other Ge photodetectors.
Article
Chemistry, Multidisciplinary
Tae Jin Yoo, Wan Sik Kim, Kyoung Eun Chang, Cihyun Kim, Min Gyu Kwon, Ji Young Jo, Byoung Hun Lee
Summary: A graphene photodetector decorated with Bi2Te3 nanowires demonstrated high gain and wide bandwidth window. The photoconductive gain was significantly improved compared to a graphene/Bi2Te3 nanoplate junction, and the position of photocurrent generation was investigated. By utilizing low bandgap Bi2Te3 nanowires and a graphene junction, the photoresponsivity was increased effectively.
Article
Nanoscience & Nanotechnology
So-Young Kim, Kiyung Kim, A. Reum Kim, Ho-In Lee, Yongsu Lee, Seung-Mo Kim, Sung Ho Yu, Hae-Won Lee, Hyeon Jun Hwang, Myung Mo Sung, Byoung Hun Lee
Summary: A novel ternary logic transistor has been developed using an ultrathin ZnO/Al2O3-AlDMP/ZnO channel, where the first ZnO layer controls the intermediate current level and the second ZnO layer controls the threshold voltage. This controllable electrical properties of the ternary device have been applied to achieve a ternary logic circuit consuming extremely low power.
ADVANCED ELECTRONIC MATERIALS
(2021)
Article
Chemistry, Physical
Seung-Mo Kim, Ho-In Lee, Yongsu Lee, So-Young Kim, Tae Jin Yoo, Sunwoo Heo, Soo Cheol Kang, Hyeon Jun Hwang, Byoung Hun Lee
Summary: A new non-destructive defect analysis method AMDCA was reported to assess the defect density and energy levels in graphene and other two-dimensional materials. The method was validated by observing charge trap densities in a graphene field-effect transistor experiment. This method can be valuable for studying graphene devices and other 2D materials without body contacts.
Article
Multidisciplinary Sciences
Woochul Kim, Hyeonghun Kim, Tae Jin Yoo, Jun Young Lee, Ji Young Jo, Byoung Hun Lee, Assa Aravindh Sasikala, Gun Young Jung, Yusin Pak
Summary: In response to the explosive demand for data processing, there has been interest in a new logic gate platform that can overcome the limitations of existing electronic logic gates. This study presents an all-in-one optoelectronic logic gate based on the spectral photo-response characteristics of a self-powered perovskite photodetector. Five representative logic gates are demonstrated using a single detector via photocurrent polarity control.
NATURE COMMUNICATIONS
(2022)
Article
Nanoscience & Nanotechnology
Cihyun Kim, Tae Jin Yoo, Min Gyu Kwon, Kyoung Eun Chang, Hyeon Jun Hwang, Byoung Hun Lee
Summary: The structure of a gate-controlled graphene/germanium hybrid photodetector was optimized by splitting the active region, resulting in significantly improved infrared detection capability.
Article
Optics
Min Gyu Kwon, Cihyun Kim, Kyoung Eun Chang, Tae Jin Yoo, So-Young Kim, Hyeon Jun Hwang, Sanghan Lee, Byoung Hun Lee
Summary: In this paper, we improved the performance of a near-infrared graphene/germanium heterojunction photodetector by doping graphene with p-type chemical, which lowered the Fermi level and increased the Schottky barrier. The responsivity and detectivity were significantly improved, making it valuable for the development of graphene/semiconductor based photodetectors and near-infrared sensors.
Article
Chemistry, Multidisciplinary
Hyeon Jun Hwang, So-Young Kim, Sang Kyung Lee, Byoung Hun Lee
Summary: By modifying the Fermi level of large-area graphene using an external electric field, researchers have experimentally investigated a reconfigurable passive device that can manipulate its resonant frequency by controlling its quantum capacitance value without complicated equipment. When the total capacitance change caused by the gate bias increased to 60% compared to the initial state, a 6% shift in the resonant frequency could be achieved. Although the signal characteristics of the graphene antenna are slightly inferior to conventional metal antennas, simplifying the device structure allows reconfigurable characteristics to be implemented using only the gate bias change.
