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排序方式: 共有232条查询结果,搜索用时 15 毫秒
1.
J. H. Lu Y. Y. Yang C. C. Chen C. H. Kuan H. T. Chen S. C. Lee 《Infrared Physics & Technology》2003,44(5-6):399-409
Superlattices have been demonstrated previously by our group in the design of the multicolor infrared photodetector. In general, the period number of the superlattice may be up to several dozens. In this paper, we have investigated the performance of the infrared photodetectors especially with 3, 5 and 15 periods. The detector structure contains a thick blocking barrier embedded between two superlattices with different period numbers but with the same well and barrier widths. This double-superlattice structure shows switchable spectral responses between two spectral regions by the voltage polarities. The photoresponse in each spectral region is also tunable by the magnitude of the applied voltage. The voltage-dependent behavior reveals the photoelectron relaxation and transport mechanism in the superlattice miniband. Superlattice with few periods has high electron group velocity, less relaxation effect and less collection efficiency. Therefore the superlattice with few periods may have better responsivity and narrower photoresponse range than the one with many periods. Based on the experimental results of our devices, it is observed that the superlattice with fewer periods has better detectivity, responsivity, wider range of the operational temperature, and more flexible miniband engineering than the conventional multiple quantum well infrared photodetector. 相似文献
2.
采用化学气相沉积法在云母衬底上制备了二维In Se纳米片,研究了生长温度对二维In Se纳米片晶相、形貌、尺寸及厚度的影响.构筑了基于二维In Se纳米片的光探测器并研究了其光探测性能,结果表明,在808 nm的近红外光辐照下,其光响应度为1. 5 A/W,外量子效率为230%,可探测度为3. 1×108Jones(1 Jones=1 cm·Hz1/2·W-1),上升和衰减时间分别为0. 5和0. 8 s. 相似文献
3.
Simulation of near-infrared photodiode detectors based on β-FeSi_2/4H-SiC heterojunctions 总被引:1,自引:0,他引:1 下载免费PDF全文
In this paper,we propose a near-infrared p-type β-FeSi2/n-type 4H-SiC heterojunction photodetector with semiconducting silicide(β-FeSi2) as the active region for the first time.The optoelectronic characteristics of the photodetector are simulated using a commercial simulator at room temperature.The results show that the photodetector has a good rectifying character and a good response to near-infrared light.Interface states should be minimized to obtain a lower reverse leakage current.The response spectrum of the β-FeSi2/4H-SiC detector,which consists of a p-type β-FeSi2 absorption layer with a doping concentration of 1×1015cm-3 and a thickness of 2.5 μm,has a peak of 755 mA/W at 1.42 μm.The illumination of the SiC side obtains a higher responsivity than that of the β-FeSi2 side.The results illustrate that the β-FeSi2/4H-SiC heterojunction can be used as a near-infrared photodetector compatible with near-infrared optically-activated SiC-based power switching devices. 相似文献
4.
Fiber‐Based Flexible All‐Solid‐State Asymmetric Supercapacitors for Integrated Photodetecting System 下载免费PDF全文
Xianfu Wang Bin Liu Rong Liu Qiufan Wang Xiaojuan Hou Prof. Di Chen Prof. Rongming Wang Prof. Guozhen Shen 《Angewandte Chemie (International ed. in English)》2014,53(7):1849-1853
Integrated nanodevices with the capability of storing energy are widely applicable and have thus been studied extensively. To meet the demand for flexible integrated devices, all‐solid‐state asymmetric supercapacitors that simultaneously realize energy storage and optoelectronic detection were fabricated by growing Co3O4 nanowires on nickel fibers, thus giving the positive electrode, and employing graphene as both the negative electrode and light‐sensitive material. The as‐assembled integrated systems were characterized by an improved energy storage, enhanced power density (at least by 1860 % enhanced) by improving the potential window from 0–0.6 V to 0—1.5 V, excellent photoresponse to white light, and superior flexibility of both the fiber‐based asymmetric supercapacitor and the photodetector. Such flexible integrated devices might be used in smart and self‐powered sensory, wearable, and portable electronics. 相似文献
5.
MoTe2是一种非空间反演对称性半导体,由线性偏振光照射,在无偏压条件下可以直接产生光电流,但是非常微弱.掺杂可以改变电子能带结构和降低空间反演对称性,从而有效的增强光电流.本文基于非平衡格林函数-密度泛函理论,采用第一性原理,计算了本征、Nb掺杂、Ti掺杂和W掺杂2H-MoTe2的能带结构、透射谱和光电流.能带结构表明:Nb掺杂使半导体2H-MoTe2能带穿越费米能级,转变为金属特性;Ti和W掺杂减小了2H-MoTe2的带隙,能带没有穿越费米能级,依然为半导体.掺杂都降低2H-MoTe2的反演对称对称性,从本征的D3h转变为Cs.从而在线偏振光的照射下可以有效的提高2H-MoTe2的光电流.同时,发现掺杂可以提高单层2H-MoTe2在低光子能量下的消光比,如Nb和Ti掺杂单层2H-MoTe2分别在光子能量1.1 eV和1.2 eV处取得39.48和28.48的高消光比... 相似文献
6.
本文制备了一种基于PdSe2/GaAs异质结的高灵敏近红外光电探测器,该探测器是通过将多层PdSe2薄膜转移到平面GaAs上制成的. 所制备的PdSe2/GaAs异质结器件在808 nm光照下表现出明显的光伏特性,这表明近红外光电探测器可以用作自驱动器件. 进一步的器件分析表明,这种杂化异质结在零偏电压和808 nm光照下具有1.16×105的高开关比. 光电探测器的响应度和比探测度分别约为171.34 mA/W和2.36×1011 Jones. 而且,该器件显示出优异的稳定性和可靠的重复性. 在空气中2个月后,近红外光电探测器的光电特性几乎没有下降,这归因于PdSe2的良好稳定性. 最后,基于PdSe2/GaAs的异质结器件还可以用作近红外光传感器. 相似文献
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9.
The symmetric Ti/Au bi-layer point electrodes have been successfully patterned on theβ-Ga;O;films which are prepared by metal–organic chemical vapor deposition(MOCVD)and theγ-Cu I films which are prepared by spin-coating.The fabricated heterojunction has a large open circuit voltage(Voc)of 0.69 V,desired for achieving self-powered operation of a photodetector.Irradiated by 254-nm ultraviolet(UV)light,when the bias voltage is-5 V,the dark current(Idark)of the device is 0.47 p A,the photocurrent(Iphoto)is-50.93 n A,and the photo-to-dark current ratio(Iphoto/Idark)reaches about 1.08×10;.The device has a stable and fast response speed in different wavelengths,the rise time(τr)and decay time(τd)are 0.762 s and 1.741 s under 254-nm UV light illumination,respectively.While theτr andτd are 10.709 s and7.241 s under 365-nm UV light illumination,respectively.The time-dependent(I–t)response(photocurrent in the order of10-10 A)can be clearly distinguished at a small light intensity of 1μW·cm;.The internal physical mechanism affecting the device performances is discussed by the band diagram and charge carrier transfer theory. 相似文献
10.
InAsSb-based nBn photodetectors were fabricated on GaAs, using the interfacial misfit (IMF) array growth mode, and on native GaSb. At −0.1 V operating bias, 200 K dark current densities of 1.4 × 10−5 A cm−2 (on GaAs) and 4.8 × 10−6 A cm−2 (on GaSb) were measured. At the same temperature, specific detectivity (D*) figures of 1.2 × 1010 Jones (on GaAs) and 7.2 × 1010 Jones (on GaSb) were calculated. Arrhenius plots of the dark current densities yielded activation energies of 0.37 eV (on GaAs) and 0.42 eV (on GaSb). These values are close to the 4 K bandgap of the absorption layers (0.32–0.35 eV) indicating diffusion limited dark currents and small valence band offsets. Significantly, these devices could be used for mid-infrared focal plane arrays operating within the temperature range of cost-effective thermoelectric coolers. 相似文献