共查询到20条相似文献,搜索用时 15 毫秒
1.
Various photodetectors showing extremely high photoresponsivity have been frequently reported, but many of these photodetectors could not avoid the simultaneous amplification of dark current. A gate‐controlled graphene–silicon Schottky junction photodetector that exhibits a high on/off photoswitching ratio (≈104), a very high photoresponsivity (≈70 A W−1), and a low dark current in the order of µA cm−2 in a wide wavelength range (395–850 nm) is demonstrated. The photoresponsivity is ≈100 times higher than that of existing commercial photodetectors, and 7000 times higher than that of graphene‐field‐effect transistor‐based photodetectors, while the dark current is similar to or lower than that of commercial photodetectors. This result can be explained by a unique gain mechanism originating from the difference in carrier transport characteristics of silicon and graphene. 相似文献
2.
Zhentao Du Dingfa Fu Jie Teng Lin Wang Fengmei Gao Weiyou Yang Hui Zhang Xiaosheng Fang 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(52)
In the present work, the exploration of photodetectors (PDs) based on CsPbI3 nanotubes are reported. The as‐prepared CsPbI3 nanotubes can be stable for more than 2 months under air conditions. It is found that, in comparison to the nanowires, nanobelts, and nanosheets, the nanotubes can be advantageous to be used as the functional units for PDs, which is mainly attributed to the enhanced light absorption ability induced by the light trapping effect within the tube cavity. As a proof of concept, the as‐constructed PDs based on CsPbI3 nanotube present an overall excellent performance with a responsivity (Rλ), external quantum efficiency (EQE) and detectivity of 1.84 × 103 A W?1, 5.65 × 105% and 9.99 × 1013 Jones, respectively, which are all comparable to state‐of‐the‐art ones for all‐inorganic perovskite PDs. 相似文献
3.
High‐Responsivity Graphene/InAs Nanowire Heterojunction Near‐Infrared Photodetectors with Distinct Photocurrent On/Off Ratios 下载免费PDF全文
Jinshui Miao Weida Hu Nan Guo Zhenyu Lu Xingqiang Liu Lei Liao Pingping Chen Tao Jiang Shiwei Wu Johnny C. Ho Lin Wang Xiaoshuang Chen Wei Lu 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(8):936-942
Graphene is a promising candidate material for high‐speed and ultra‐broadband photodetectors. However, graphene‐based photodetectors suffer from low photoreponsivity and Ilight/Idark ratios due to their negligible‐gap nature and small optical absorption. Here, a new type of graphene/InAs nanowire (NW) vertically stacked heterojunction infrared photodetector is reported, with a large photoresponsivity of 0.5 AW?1 and Ilight/Idark ratio of 5 × 102, while the photoresponsivity and Ilight/Idark ratio of graphene infrared photodetectors are 0.1 mAW?1 and 1, respectively. The Fermi level (EF ) of graphene can be widely tuned by the gate voltage owing to its 2D nature. As a result, the back‐gated bias can modulate the Schottky barrier (SB) height at the interface between graphene and InAs NWs. Simulations further demonstrate the rectification behavior of graphene/InAs NW heterojunctions and the tunable SB controls charge transport across the vertically stacked heterostructure. The results address key challenges for graphene‐based infrared detectors, and are promising for the development of graphene electronic and optoelectronic applications. 相似文献
4.
5.
Xiaodong Li Caitian Gao Huigao Duan Bingan Lu Youqing Wang Lulu Chen Zhenxing Zhang Xiaojun Pan Erqing Xie 《Small (Weinheim an der Bergstrasse, Germany)》2013,9(11):2005-2011
TiO2/SnO2 branched heterojunction nanostructure with TiO2 branches on electrospun SnO2 nanofiber (B‐SnO2 NF) networks serves as a model architecture for efficient self‐powered UV photodetector based on a photoelectrochemical cell (PECC). The nanostructure simultaneously offers a low degree of charge recombination and a direct pathway for electron transport. Without correcting 64.5% loss of incident photons through light absorption and scattering by the F‐doped tin oxide (FTO) glass, the incident power conversion efficiency reaches 14.7% at 330 nm, more than twice as large as the nanocrystalline TiO2 (TiO2 NC, 6.4%)‐film based PECC. By connecting a PECC to an ammeter, the intensity of UV light is quantified using the output short‐circuit photocurrent density (Jsc) without a power source. Under UV irradiation, the self‐powered UV photodetector exhibits a high responsivity of 0.6 A/W, a high on/off ratio of 4550, a rise time of 0.03 s and a decay time of 0.01 s for Jsc signal. The excellent performance of the B‐SnO2 NF‐based PECC type self‐powered photodetector will enable significant advancements for next‐generation photodetection and photosensing applications. 相似文献
6.
Vinh Quang Dang Tran Quang Trung Do‐Il Kim Le Thai Duy Byeong‐Ung Hwang Doo‐Won Lee Bo‐Yeong Kim Le Duc Toan Nae‐Eung Lee 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(25):3054-3065
Ultraviolet (UV) photodetectors based on ZnO nanostructure/graphene (Gr) hybrid‐channel field‐effect transistors (FETs) are investigated under illumination at various incident photon intensities and wavelengths. The time‐dependent behaviors of hybrid‐channel FETs reveal a high sensitivity and selectivity toward the near‐UV region at the wavelength of 365 nm. The devices can operate at low voltage and show excellent selectivity, high responsivity (RI ), and high photoconductive gain (G). The change in the transfer characteristics of hybrid‐channel FETs under UV light illumination allows to detect both photovoltage and photocurrent. The shift of the Dirac point (V Dirac) observed during UV exposure leads to a clearer explanation of the response mechanism and carrier transport properties of Gr, and this phenomenon permits the calculation of electron concentration per UV power density transferred from ZnO nanorods and ZnO nanoparticles to Gr, which is 9 × 1010 and 4 × 1010 per mW, respectively. The maximum values of RI and G infer from the fitted curves of RI and G versus UV intensity are 3 × 105 A W?1 and 106, respectively. Therefore, the hybrid‐channel FETs studied herein can be used as UV sensing devices with high performance and low power consumption, opening up new opportunities for future optoelectronic devices. 相似文献
7.
Linlin Li Hao Xu Zhexin Li Lingchen Liu Zheng Lou Lili Wang 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(42):2303114
High-quality photodetectors are always the main way to obtain external information, especially near-infrared sensors play an important role in remote sensing communication. However, due to the limitation of Silicon (Si) wide bandgap and the incompatibility of most near infrared photoelectric materials with traditional integrated circuits, the development of high performance and wide detection spectrum near infrared detectors suitable for miniaturization and integration is still facing many obstacles. Herein, the monolithic integration of large area tellurium optoelectronic functional units is realized by magnetron sputtering technology. Taking advantage of the type II heterojunction constructed by tellurium (Te) and silicon (Si), the photogenerated carriers are effectively separated, which prolongs the carrier lifetime and improves the photoresponse by several orders of magnitude. The tellurium/silicon (Te/Si) heterojunction photodetector demonstrates excellent detectivity and ultra-fast turn-on time. Importantly, an imaging array (20 × 20 pixels) based on the Te/Si heterojunction is demonstrated and high-contrast photoelectric imaging is realized. Because of the high contrast obtained by the Te/Si array, in comparison with the Si arrays, it significantly improve the efficiency and accuracy of the subsequent processing tasks when the electronic pictures are applied to artificial neural network (ANN) to simulate the artificial vision system. 相似文献
8.
A Self‐Powered and Flexible Organometallic Halide Perovskite Photodetector with Very High Detectivity 下载免费PDF全文
Siu‐Fung Leung Kang‐Ting Ho Po‐Kai Kung Vincent K. S. Hsiao Husam N. Alshareef Zhong Lin Wang Jr‐Hau He 《Advanced materials (Deerfield Beach, Fla.)》2018,30(8)
Flexible and self‐powered photodetectors (PDs) are highly desirable for applications in image sensing, smart building, and optical communications. In this paper, a self‐powered and flexible PD based on the methylammonium lead iodide (CH3NH3PBI3) perovskite is demonstrated. Such a self‐powered PD can operate even with irregular motion such as human finger tapping, which enables it to work without a bulky external power source. In addition, with high‐quality CH3NH3PBI3 perovskite thin film fabricated with solvent engineering, the PD exhibits an impressive detectivity of 1.22 × 1013 Jones. In the self‐powered voltage detection mode, it achieves a large responsivity of up to 79.4 V mW?1 cm?2 and a voltage response of up to ≈90%. Moreover, as the PD is made of flexible and transparent polymer films, it can operate under bending and functions at 360 ° of illumination. As a result, the self‐powered, flexible, 360 ° omnidirectional perovskite PD, featuring high detectivity and responsivity along with real‐world sensing capability, suggests a new direction for next‐generation optical communications, sensing, and imaging applications. 相似文献
9.
Andrew Wadsworth Zeinab Hamid Jan Kosco Nicola Gasparini Iain McCulloch 《Advanced materials (Deerfield Beach, Fla.)》2020,32(38):2001763
Organic semiconductors require an energetic offset in order to photogenerate free charge carriers efficiently, owing to their inability to effectively screen charges. This is vitally important in order to achieve high power conversion efficiencies in organic solar cells. Early heterojunction-based solar cells were limited to relatively modest efficiencies (<4%) owing to limitations such as poor exciton dissociation, limited photon harvesting, and high recombination losses. The development of the bulk heterojunction (BHJ) has significantly overcome these issues, resulting in dramatic improvements in organic photovoltaic performance, now exceeding 18% power conversion efficiencies. Here, the design and engineering strategies used to develop the optimal bulk heterojunction for solar-cell, photodetector, and photocatalytic applications are discussed. Additionally, the thermodynamic driving forces in the creation and stability of the bulk heterojunction are presented, along with underlying photophysics in these blends. Finally, new opportunities to apply the knowledge accrued from BHJ solar cells to generate free charges for use in promising new applications are discussed. 相似文献
10.
High Detectivity and Transparent Few‐Layer MoS2/Glassy‐Graphene Heterostructure Photodetectors 下载免费PDF全文
Hao Xu Xiaoyu Han Xiao Dai Wei Liu Jiang Wu Juntong Zhu Dongyoung Kim Guifu Zou Kimberley A. Sablon Andrei Sergeev Zhengxiao Guo Huiyun Liu 《Advanced materials (Deerfield Beach, Fla.)》2018,30(13)
Layered van der Waals heterostructures have attracted considerable attention recently, due to their unique properties both inherited from individual two‐dimensional (2D) components and imparted from their interactions. Here, a novel few‐layer MoS2/glassy‐graphene heterostructure, synthesized by a layer‐by‐layer transfer technique, and its application as transparent photodetectors are reported for the first time. Instead of a traditional Schottky junction, coherent ohmic contact is formed at the interface between the MoS2 and the glassy‐graphene nanosheets. The device exhibits pronounced wavelength selectivity as illuminated by monochromatic lights. A responsivity of 12.3 mA W?1 and detectivity of 1.8 × 1010 Jones are obtained from the photodetector under 532 nm light illumination. Density functional theory calculations reveal the impact of specific carbon atomic arrangement in the glassy‐graphene on the electronic band structure. It is demonstrated that the band alignment of the layered heterostructures can be manipulated by lattice engineering of 2D nanosheets to enhance optoelectronic performance. 相似文献
11.
12.
Sam Gielen Christina Kaiser Frederik Verstraeten Jonas Kublitski Johannes Benduhn Donato Spoltore Pieter Verstappen Wouter Maes Paul Meredith Ardalan Armin Koen Vandewal 《Advanced materials (Deerfield Beach, Fla.)》2020,32(47):2003818
Organic photodetectors (OPDs) with a performance comparable to that of conventional inorganic ones have recently been demonstrated for the visible regime. However, near-infrared photodetection has proven to be challenging and, to date, the true potential of organic semiconductors in this spectral range (800–2500 nm) remains largely unexplored. In this work, it is shown that the main factor limiting the specific detectivity (D*) is non-radiative recombination, which is also known to be the main contributor to open-circuit voltage losses. The relation between open-circuit voltage, dark current, and noise current is demonstrated using four bulk-heterojunction devices based on narrow-gap donor polymers. Their maximum achievable D* is calculated alongside a large set of devices to demonstrate an intrinsic upper limit of D* as a function of the optical gap. It is concluded that OPDs have the potential to be a useful technology up to 2000 nm, given that high external quantum efficiencies can be maintained at these low photon energies. 相似文献
13.
14.
Novel UV–Visible Photodetector in Photovoltaic Mode with Fast Response and Ultrahigh Photosensitivity Employing Se/TiO2 Nanotubes Heterojunction 下载免费PDF全文
Lingxia Zheng Kai Hu Feng Teng Xiaosheng Fang 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(5)
A feasible strategy for hybrid photodetector by integrating an array of self‐ordered TiO2 nanotubes (NTs) and selenium is demonstrated to break the compromise between the responsivity and response speed. Novel heterojunction between the TiO2 NTs and Se in combination with the surface trap states at TiO2 help regulate the electron transport and facilitate the separation of photogenerated electron–hole pairs under photovoltaic mode (at zero bias), leading to a high responsivity of ≈100 mA W?1 at 620 nm light illumination and the ultrashort rise/decay time (1.4/7.8 ms). The implanting of intrinsic p‐type Se into TiO2 NTs broadens the detection range to UV–visible (280–700 nm) with a large detectivity of over 1012 Jones and a high linear dynamic range of over 80 dB. In addition, a maximum photocurrent of ≈107 A is achieved at 450 nm light illumination and an ultrahigh photosensitivity (on/off ratio up to 104) under zero bias upon UV and visible light illumination is readily achieved. The concept of employing novel heterojunction geometry holds great potential to pave a new way to realize high performance and energy‐efficient optoelectronic devices for practical applications. 相似文献
15.
In Situ Fabrication of Vertical Multilayered MoS2/Si Homotype Heterojunction for High‐Speed Visible–Near‐Infrared Photodetectors 下载免费PDF全文
Yan Zhang Yongqiang Yu Longfei Mi Hui Wang Zhifeng Zhu Qingyun Wu Yugang Zhang Yang Jiang 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(8):1062-1071
c2D transition metal dichalcogenides (TMDCs)‐based heterostructures have been demonstrated to achieve superior light absorption and photovoltaic effects theoretically and experimentally, making them extremely attractive for realizing optoelectronic devices. In this work, a vertical multilayered n‐MoS2/n‐silicon homotype heterojunction is fabricated, which takes advantage of multilayered MoS2 grown in situ directly on plane silicon. Electrical characterization reveals that the resultant device exhibits high sensitivity to visible–near‐infrared light with responsivity up to 11.9 A W–1. Notably, the photodetector shows high‐speed response time of ≈30.5 µs/71.6 µs and capability to work under higher pulsed light irradiation approaching 100 kHz. The high response speed could be attributed to a good quality of the multilayer MoS2, as well as in situ device fabrication process. These findings suggest that the multilayered MoS2/Si homotype heterojunction have great potential application in the field of visible–near‐infrared detection and might be used as elements for construction of high‐speed integrated optoelectronic sensor circuitry. 相似文献
16.
17.
Graphene/Si‐Quantum‐Dot Heterojunction Diodes Showing High Photosensitivity Compatible with Quantum Confinement Effect 下载免费PDF全文
Dong Hee Shin Sung Kim Jong Min Kim Chan Wook Jang Ju Hwan Kim Kyeong Won Lee Jungkil Kim Si Duck Oh Dae Hun Lee Soo Seok Kang Chang Oh Kim Suk‐Ho Choi Kyung Joong Kim 《Advanced materials (Deerfield Beach, Fla.)》2015,27(16):2614-2620
18.
Ferroelectric Localized Field–Enhanced ZnO Nanosheet Ultraviolet Photodetector with High Sensitivity and Low Dark Current 下载免费PDF全文
Peng Wang Yang Wang Lei Ye Mingzai Wu Runzhang Xie Xudong Wang Xiaoshuang Chen Zhiyong Fan Jianlu Wang Weida Hu 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(22)
Zinc oxide (ZnO) nanosheets have demonstrated outstanding electrical and optical properties, which are well suited for ultraviolet (UV) photodetectors. However, they have a high density of intrinsically unfilled traps, and it is difficult to achieve p‐type doping, leading to the poor performance for low light level switching ratio and a high dark current that limit practical applications in UV photodetection. Here, UV photodetectors based on ZnO nanosheets are demonstrated, whose performance is significantly improved by using a ferroelectric localized field. Specifically, the photodetectors have achieved a responsivity of up to 3.8 × 105 A W?1, a detectivity of 4.4 × 1015 Jones, and a photocurrent gain up to 1.24 × 106. These device figures of merit are far beyond those of traditional ZnO ultraviolet photodetectors. In addition, the devices' initial dark current can be easily restored after continuous photocurrent measurement by using a positive gate voltage pulse. This study establishes a new approach to produce high‐sensitivity and low‐dark‐current ultraviolet photodetectors and presents a crucial step for further practical applications. 相似文献
19.
Jianting Lu Zhaoqiang Zheng Jiandong Yao Wei Gao Yu Zhao Ye Xiao Jingbo Li 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(47)
Silicon‐based electronic devices, especially graphene/Si photodetectors (Gr/Si PDs), have triggered tremendous attention due to their simple structure and flexible integration of the Schottky junction. However, due to the relatively poor light–matter interaction and mobility of silicon, these Gr/Si PDs typically suffer an inevitable compromise between photoresponsivity and response speed. Herein, a novel strategy for coupling 2D In2S3 with Gr/Si PDs is demonstrated. The introduction of the double‐heterojunction design not only strengthens the light absorption of graphene/Si but also combines the advantages of the photogating effect and photovoltaic effect, which suppresses the dark current, accelerates the separation of photogenerated carriers, and brings photoconductive gain. As a result, In2S3/graphene/Si devices present an ultrahigh photoresponsivity of 4.53 × 104 A W?1 and fast response speed less than 40 µs, simultaneously. These parameters are an order of magnitude higher than pristine Gr/Si PDs and among the best values compared with reported 2D materials/Si heterojunction PDs. Furthermore, the In2S3/graphene/Si PD expresses outstanding long‐term stability, with negligible performance degradation even after 1 month in air or 1000 cycles of operation. These findings highlight a simple and novel strategy for constructing high‐sensitivity and ultrafast Gr/Si PDs for further optoelectronic applications. 相似文献