Marshall Space Flight Center Research and Technology Report 2019

Today, our calling to explore is greater than ever before, and here at Marshall Space Flight Centerwe make human deep space exploration possible. A key goal for Artemis is demonstrating and perfecting capabilities on the Moon for technologies needed for humans to get to Mars. This years report features 10 of the Agencys 16 Technology Areas, and I am proud of Marshalls role in creating solutions for so many of these daunting technical challenges. Many of these projects will lead to sustainable in-space architecture for human space exploration that will allow us to travel to the Moon, on to Mars, and beyond. Others are developing new scientific instruments capable of providing an unprecedented glimpse into our universe. NASA has led the charge in space exploration for more than six decades, and through the Artemis program we will help build on our work in low Earth orbit and pave the way to the Moon and Mars. At Marshall, we leverage the skills and interest of the international community to conduct scientific research, develop and demonstrate technology, and train international crews to operate further from Earth for longer periods of time than ever before first at the lunar surface, then on to our next giant leap, human exploration of Mars. While each project in this report seeks to advance new technology and challenge conventions, it is important to recognize the diversity of activities and people supporting our mission. This report not only showcases the Centers capabilities and our partnerships, it also highlights the progress our people have achieved in the past year. These scientists, researchers and innovators are why Marshall and NASA will continue to be a leader in innovation, exploration, and discovery for years to come

Magnetotransport properties of rare earth element modified carbon nanotubes

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Doctor of Philosophy. University of the Witwatersrand JohannesburgFunctionalization and filling of carbon nanotubes has been tailored over years to modify the exceptional properties of the 1-dimensional (1D) conductor for magnetic properties based applications. Hence such a system exploits the spin and charge property of the electron, analogous to a quantum conductor coupled to magnetic impurities which poses an interesting scenario for the study of Kondo physics and related phenomena. A study of the low temperature electronic transport and magnetic properties of carbon nanotubes modified with gadolinium derivatives is presented in this thesis. The methods of modification used are chemical functionalization and capillary filling. The presence of gadolinium in the nanostructures extends the functionality of the nanotubes from conventional electronics to spintronics. Filled and functionalized multiwalled carbon nanotubes are characterized as well as filled double walled carbon nanotubes. This system gives a chance to study the interaction of a ballistic conductor with magnetic impurities. Multiwalled carbon nanotubes functionalized with a gadolinium based supramolecular complex show enhanced magnetic properties and unexpected electronic behaviour that has not been observed in this material before. A newly developed synthesis technique has been employed for the synthesis and it is found that the functionalization method of the nanocomposite enhances the strength of magnetic interaction leading to a large effective moment of 15.79 μB and non-superparamagnetic behaviour unlike what has been previously reported. Saturating resistance at low temperatures is fitted with the numerical renormalization group formula verifying the Kondo effect for magnetic impurities on a metallic electron system. Magnetoresistance shows that devices fabricated from aligned gadolinium functionalized MWNTs exhibit spin-valve switching behaviour of up to 8%. The electronic transport properties of MWNTs filled with GdCl3 nanomagnets clearly shows the co-existence of Kondo correlation and cotunelling within the superparamagnetic limit. The Fermi liquid description of the Kondo effect and the interpolation scheme are fitted to the resistance-temperature dependence yielding the onset of the Kondo scattering temperature and a Kondo temperature for this nanocomposite, respectively. Cotunneling of conduction electrons inhibiting a Kondo type interaction has been verified from the exponential decay of the intensity of the fano shaped non zero bias anomalous conductance peaks which also show strong resonant features observed only in GdCl3 filled MWNT devices. Hence these features are explained in terms of magnetic coherence and spin-flip effects along with the competition between the Kondo effect and co-tunneling. The properties of doublewalled carbon naotubes filled with GdCl3 are also presented. They show superparamagnetic behaviour and zero bias anomalies similar to what was observed in Gd filled MWNTs. This work is the first on such lanthanide modified CNT hybrid bundle devices. The study raises a new possibility of tailoring magnetic interactions for spintronic applications in carbon nanotube systems. It highlights the possibility of enhancing magnetic interactions in carbon systems through chemical modification. Furthermore, the study demonstrates the rich physics that might be useful for developing spin-based quantum computing elements based on 1D channels.MT 201

DEVELOPMENT OF INFRARED AND TERAHERTZ BOLOMETERS BASED ON PALLADIUM AND CARBON NANOTUBES USING ROLL TO ROLL PROCESS

Terahertz region in the electromagnetic spectrum is the region between Infrared and Microwave. As the Terahertz region has both wave and particle nature, it is difficult to make a room temperature, fast, and sensitive detector in this region. In this work, we fabricated a Palladium based IR detector and a CNT based THz bolometer. In Chapter 1, I give a brief introduction of the Terahertz region, the detectors already available in the market and different techniques I can use to test my detector. In Chapter 2, I explain about the Palladium IR bolometer, the fabrication technique I have used, and then we discuss the performance of the detector. In Chapter 3, I explained about the Roll to Roll based THz bolometer, its working and fabrication techniques, and at the end we discussed its performance

APPLICATION OF SINGLE WALLED CARBON NANOTUBES IN ENVIRONMENTAL ENGINEERING: ADSORPTION AND DESORPTION OF ENVIRONMENTALLY RELEVANT SPECIES STUDIED BY INFRARED SPECTROSCOPY AND TEMPERATURE PROGRAMMED DESORPTION

This study evaluated the environmental applications of carbon nanotubes through the adsorption and desorption of representative environmentally relevant adsorbates; ammonia, hydrogen sulfide and acetone under ultra high vacuum (UHV) and high pressure conditions. The results showed that functionalities/defects sites on nanotube surfaces play an important role on the interaction between molecules and carbon nanotubes. The oxygen containing functional groups on single-walled carbon nanotubes (SWNTs) are studied by Fourier Transform Infrared (FTIR) spectroscopy under vacuum. Vacuum heating to ~ 1300 K removes most of the functionalities in the samples. The similarities in the infrared spectra of the Rice Tubes after a 1400 K treatment with spectra for HiPco nanotubes suggest the observation of intrinsic SWNT IR bands.Ammonia adsorption on single walled carbon nanotubes (SWNTs) was studied in order to investigate the environmental application of nanotubes, mainly possible uses as sensors. At 94 K, vacuum annealed SWNTs showed no detectable ammonia uptake. However, the ammonia adsorption was found to be sensitive to the functionalities and defects on the nanotube surfaces. NH3 desorbed from those nanotubes above 140 K, indicating a weak adsorbate-nanotube interaction (~30 kJ/mol). This work suggests the influence of functionalities and/or defect densities on the sensitivity of SWNT chemical gas sensors. Both physisorption and chemisorption of acetone on nanotubes were observed. It was found that H2S adsorbed on nanotube surfaces at cryogenic temperature but not at room temperature. The low desorption temperature suggests only physisorption of H2S on nanotubes.In this study, low concentration of functionalities on carbon material surfaces was detected by fluorescent labeling technique. Florescent labeling indicated the presence of COOH and CHO groups on the ACF 25 fiber surface. Neither the infrared spectrum nor the X-ray photoelectron spectrum showed evidence of the existence of those low concentration groups. The key findings of this work make it possible that applying scientific information obtained from studies under ideal conditions to industrial sorbents/sensors under realistic process conditions. Nanotube surfaces can be modified chemically to enhance their affinities for certain kinds of gas molecules

NASA Tech Briefs, June 2012

Topics covered include: iGlobe Interactive Visualization and Analysis of Spatial Data; Broad-Bandwidth FPGA-Based Digital Polyphase Spectrometer; Small Aircraft Data Distribution System; Earth Science Datacasting v2.0; Algorithm for Compressing Time-Series Data; Onboard Science and Applications Algorithm for Hyperspectral Data Reduction; Sampling Technique for Robust Odorant Detection Based on MIT RealNose Data; Security Data Warehouse Application; Integrated Laser Characterization, Data Acquisition, and Command and Control Test System; Radiation-Hard SpaceWire/Gigabit Ethernet-Compatible Transponder; Hardware Implementation of Lossless Adaptive Compression of Data From a Hyperspectral Imager; High-Voltage, Low-Power BNC Feedthrough Terminator; SpaceCube Mini; Dichroic Filter for Separating W-Band and Ka-Band; Active Mirror Predictive and Requirement Verification Software (AMP-ReVS); Navigation/Prop Software Suite; Personal Computer Transport Analysis Program; Pressure Ratio to Thermal Environments; Probabilistic Fatigue Damage Program (FATIG); ASCENT Program; JPL Genesis and Rapid Intensification Processes (GRIP) Portal; Data::Downloader; Fault Tolerance Middleware for a Multi-Core System; DspaceOgreTerrain 3D Terrain Visualization Tool; Trick Simulation Environment 07; Geometric Reasoning for Automated Planning; Water Detection Based on Color Variation; Single-Layer, All-Metal Patch Antenna Element with Wide Bandwidth; Scanning Laser Infrared Molecular Spectrometer (SLIMS); Next-Generation Microshutter Arrays for Large-Format Imaging and Spectroscopy; Detection of Carbon Monoxide Using Polymer-Composite Films with a Porphyrin-Functionalized Polypyrrole; Enhanced-Adhesion Multiwalled Carbon Nanotubes on Titanium Substrates for Stray Light Control; Three-Dimensional Porous Particles Composed of Curved, Two-Dimensional, Nano-Sized Layers for Li-Ion Batteries 23 Ultra-Lightweight; and Ultra-Lightweight Nanocomposite Foams and Sandwich Structures for Space Structure Applications

NASA Tech Briefs, October 2003

Topics covered include: Cryogenic Temperature-Gradient Foam/Substrate Tensile Tester; Flight Test of an Intelligent Flight-Control System; Slat Heater Boxes for Thermal Vacuum Testing; System for Testing Thermal Insulation of Pipes; Electrical-Impedance-Based Ice-Thickness Gauges; Simulation System for Training in Laparoscopic Surgery; Flasher Powered by Photovoltaic Cells and Ultracapacitors; Improved Autoassociative Neural Networks; Toroidal-Core Microinductors Biased by Permanent Magnets; Using Correlated Photons to Suppress Background Noise; Atmospheric-Fade-Tolerant Tracking and Pointing in Wireless Optical Communication; Curved Focal-Plane Arrays Using Back-Illuminated High-Purity Photodetectors; Software for Displaying Data from Planetary Rovers; Software for Refining or Coarsening Computational Grids; Software for Diagnosis of Multiple Coordinated Spacecraft; Software Helps Retrieve Information Relevant to the User; Software for Simulating a Complex Robot; Software for Planning Scientific Activities on Mars; Software for Training in Pre-College Mathematics; Switching and Rectification in Carbon-Nanotube Junctions; Scandia-and-Yttria-Stabilized Zirconia for Thermal Barriers; Environmentally Safer, Less Toxic Fire-Extinguishing Agents; Multiaxial Temperature- and Time-Dependent Failure Model; Cloverleaf Vibratory Microgyroscope with Integrated Post; Single-Vector Calibration of Wind-Tunnel Force Balances; Microgyroscope with Vibrating Post as Rotation Transducer; Continuous Tuning and Calibration of Vibratory Gyroscopes; Compact, Pneumatically Actuated Filter Shuttle; Improved Bearingless Switched-Reluctance Motor; Fluorescent Quantum Dots for Biological Labeling; Growing Three-Dimensional Corneal Tissue in a Bioreactor; Scanning Tunneling Optical Resonance Microscopy; The Micro-Arcsecond Metrology Testbed; Detecting Moving Targets by Use of Soliton Resonances; and Finite-Element Methods for Real-Time Simulation of Surgery

Cryogenic Processing of \u3cem\u3eAl 7050-T7451\u3c/em\u3e Alloy for Improved Surface Integrity

Al 7050-T7451 alloy with good combinations of strength, stress corrosion cracking resistance and toughness, is used broadly in the aerospace/aviation industry for fatigue-critical airframe structural components. However, it is also considered as a highly anisotropic alloy as the crack growth behavior along the short transverse direction is very different from the one in the long transverse direction, due to the inhomogeneous microstructure with the elongated grains distributed in the work material used in the sheet/plate applications. Further processes on these materials are needed to improve its mechanical and material properties and broaden its applications. The material with ultra-fine or nano grains exhibits improved wear and corrosion resistance, higher hardness and better fatigue life, compared to the one with coarse grains. In recent times, the development of novel processing technologies has gained great attention in the research community to enhance the properties of the materials employed in the aerospace, biomedical, precision instrument, automotive, nuclear/power industries. These novel processing technologies modify the microstructure of this alloy and improve the properties. The aim of this dissertation is to investigate the effects of cryogenic processes, including friction stir processing (FSP), machining and burnishing, on Al 7050-T7451 alloy to solve the inhomogeneity issue and improve its surface integrity. FSP is applied to modify the microstructure of Al 7050-T7451 alloy for achieving more homogeneous structure with near ultra-fine grains (UFG) which were less than 2 µm, particularly in cryogenic FSP with liquid nitrogen as the coolant. Approximately 10% increase could be observed from the hardness measurement from the samples processed by cryogenic FSP, in contrast to dry FSP. Also, the texture change from Al (200) to Al (111) could be achieved in all the samples processed by dry and cryogenic FSP. Cryogenic machining and burnishing processes were also applied to enhance the surface integrity of the manufactured components with near-UFG structure. The highest cutting temperature was reduced by up to 44.7% due to the rapid cooling effect of liquid nitrogen in cryogenic machining, compared with dry machining. Nano grains were produced in the refined layers induced by cryogenic burnishing. And, up to 35.4% hardness increase was obtained within the layer depth of 200 µm in the cryogenically-burnished surface. A numerical finite element method (FEM) model was developed for predicting the process performance in burnishing. Less than 10% difference between the experimental and predicted burnishing forces was achieved in the simulation of cryogenic burnishing, and reasonable predictions were also achieved for temperatures, severe plastic deformation (SPD) layers

Future Missions to Titan: Scientific and Engineering Challenges

Saturn’s largest moon, Titan, has been an enigma at every stage of its exploration. For three decades after the hazy atmosphere was discovered from the ground in the 1940s, debate ensued over whether it was a thin layer of methane or a dense shield of methane and nitrogen. Voyager 1 settled the matter in favor of the latter in 1980, but the details of the thick atmosphere discovered raised even more intriguing questions about the nature of the hidden surface, and the sources of resupply of methane to the atmosphere. The simplest possibility, that an ocean of methane and its major photochemical product ethane might cover the globe, was cast in doubt by Earth-based radar studies and then eliminated by Hubble Space Telescope and adaptive optics imaging in the near-infrared from large ground-based telescopes in the 1990s. These data, however, did not reveal the complexity of the surface that Cassini-Huygens would uncover beginning in 2004. A hydrological cycle appears to exist in which methane (in concert with ethane in some processes) plays the role on Titan that water plays on Earth. Channels likely carved by liquid methane and/or ethane, lakes and seas of these materials—some rivaling or exceeding North America’s Great Lakes in size—vast equatorial dune fields of complex organics made high in the atmosphere and shaped by wind, and intriguing hints of geologic activity suggest a world with a balance of geologic and atmospheric processes that is the solar system’s best analogue to Earth. Deep underneath Titan’s dense atmosphere and active, diverse surface is an interior ocean discovered by Cassini and thought to be largely composed of liquid water. Cassini-Huygens has provided spectacular data and has enabled us to glimpse the mysterious surface of Titan. However the mission will leave us with many questions that require future missions to answer. These include determining the composition of the surface and the geographic distribution of various organic constituents. Key questions remain about the ages of surface features, specifically whether cryovolcanism and tectonism are actively ongoing or are relics of a more active past. Ammonia, circumstantially suggested to be present by a variety of different kinds of Cassini-Huygens data, has yet to be seen. Is methane out-gassing from the interior or ice crust today? Are the lakes fed primarily by rain or underground methane-ethane aquifers (more properly, “alkanofers”) and how often have heavy methane rains come to the equatorial region? We should investigate whether Titan’s surface supported vaster seas of methane in the past, and whether complex self-organizing chemical systems have come and gone in the water volcanism, or even exist in exotic form today in the high latitude lakes. The presence of a magnetic field has yet to be established. A large altitude range in the atmosphere, from 400–900 km in altitude, will remain poorly explored after Cassini. Much remains to be understood about seasonal changes of the atmosphere at all levels, and the long-term escape of constituents to space. Other than Earth, Titan is the only world in our solar system known to have standing liquids and an active “hydrologic cycle” with clouds, rains, lakes and streams. The dense atmosphere and liquid lakes on Titan’s surface can be explored with airborne platforms and landed probes, but the key aspect ensuring the success of future investigations is the conceptualization and design of instruments that are small enough to fit on the landed probes and airborne platforms, yet sophisticated enough to conduct the kinds of detailed chemical (including isotopic), physical, and structural analyses needed to investigate the history and cycling of the organic materials. In addition, they must be capable of operating at cryogenic temperatures while maintaining the integrity of the sample throughout the analytic process. Illuminating accurate chemistries also requires that the instruments and tools are not simultaneously biasing the measurements due to localized temperature increases. While the requirements for these techniques are well understood, their implementation in an extremely low temperature environment with limited mass, power and volume is acutely challenging. No such instrument systems exist today. Missions to Titan are severely limited in both mass and power because spacecraft have to travel over a billion miles to get there and require a large amount of fuel, not only to reach Titan, but to maintain the ability to maneuver when they arrive. Landed missions have additional limitations, in that they must be packaged in a sealed aeroshell for entry into Titan’s atmosphere. Increases in landed mass and volume translate to increased aeroshell mass and size, requiring even more fuel for delivery to Titan. Nevertheless, missions during which such systems and instruments could be employed range from Discovery and New Frontiers class in situ probes that might be launched in the next decade, to a full-up Flagship class mission anticipated to follow the Europa Jupiter System Mission. Capitalizing on recent breakthroughs in cryo-technologies and smart materials fabrication, we developed conceptual designs of sample acquisition systems and instruments capable of in situ operation under low temperature environments. The study included two workshops aimed at brainstorming and actively discussing a broad range of ideas and associated challenges with landing instruments on Titan, as well as more focused discussions during the intervening part of the study period. The workshops each lasted ~4 days (Monday-Thursday/Friday), included postdoctoral fellows and students in addition to the core team members, and generated active engagement from the Caltech and JPL team participants, as well as from the outside institutions. During the workshops, new instruments and sampling methodologies were identified to handle the challenges of characterizing everything from small molecules in Titan’s upper atmosphere to gross mixtures of high molecular weight complex organics in condensed phases, including atmospheric aerosols and “organic sand” in dunes, to highly dilute components in ices and lakes. To enable these advances in cryogenic instrumentation breakthroughs in a wide range of disciplines, including electronics, chemical and mechanical engineering, and materials science were identified

FET 플랫폼을 기반으로 한 저온에서의 이산화탄소 감지

학위논문 (박사)-- 서울대학교 대학원 : 공과대학 전기·정보공학부, 2019. 2. 이종호.지난 수십 년 동안 이산화탄소(CO2)를 감지하고 제어하는 기술은 많은 관심을 받아왔다. 이산화탄소의 양을 감지하는 것은 대기의 질이 어떻게 변화하는지를 추적하는데 중요할 뿐만 아니라 관련 환경 연구에서도 중요하다. 또한 실내공기 내의 이산화탄소는 사람에게 질병을 유발할 수 있기 때문에 실내 이산화탄소 농도를 특정 기준 이하로 제어하는 것이 중요하다. 지금까지의 연구들은 낮은 비용, 작은 크기, 적은 전력 소비, 높은 신뢰성을 가진 CO2 센서를 개발하기 위해 노력하였다. 뿐만 아니라 실리콘 CMOS 센서 처리회로와 호환 가능한 센서 어레이를 만들 수 있으며 휴대 가능한 전자 코 시스템(electronic nose system)에도 응용할 수 있는 집적 가능한 CO2 센서의 수요도 증가하고 있다. 따라서 본 논문에서는 저온에서 작동하는 FET형 CO2 센서를 제안하고 폴리비닐 알콜(PVA), 폴리에틸렌이민(PEI)로 코팅된 단일벽 탄소나노튜브(SWNT), 무기 Na+ 이온 전도성 물질과 같은 다양한 종류의 감지 물질을 적용하였다. 감지 물질은 잉크젯 프린팅 공정을 사용하여 FET 센서 플랫폼에 증착되었다. 센서의 기본적인 전기적 특성과 CO2 감지 특성을 측정하였다. 이와 관련된 감지 동작 원리를 설명하고 모델링하였다. PVA와 PEI로 코팅된 단일벽 탄소나노튜브 CO2 센서는 습도의 도움을 받아 상온(약 25ºC)에서 CO2를 검출 할 수 있다. Na+ 이온 전도성 물질을 가진 센서는 160ºC에서 CO2를 검출 할 수 있다. 제안된 센서는 기존의 CO2 센서에 비해 상대적으로 낮은 작동 온도를 갖는다. 또한 FET형 센서는 실리콘 CMOS 기술과 호환가능하다. 센서의 캘리브레이션을 편리하게 만들기 위해 플로팅 게이트 구조를 채택하였다. 다른 감지 물질들에 비해 Na+ 이온 전도성 물질을 갖는 센서는 습도의 도움을 받지 않고 감지 가능하며 가장 안정한 감지 특성을 가진다. 또한 저온에서의 CO2 검출에 매우 효과적일 것으로 기대된다.In the past few decades, carbon dioxide (CO2) monitoring and controlling have attracted a lot of attentions. The monitoring of CO2 outdoor helps researchers to know the change in the quality of the atmospheric air and provides important data for environment research. In the aspect of indoor air quality controlling, it is also important to detect and restrain the CO2 concentration under a certain level, because high CO2 concentration indoor can trigger symptoms and affect human health. By now, many efforts have been made to develop reliable CO2 sensors with long life time, low cost, small size, low power consumption, and low working temperature. Moreover, integratable CO2 sensor is desired in order to manufacture gas arrays that are compatible with silicon CMOS technology, and extend its application in the field of portable electronic nose system. In this dissertation, the CO2 sensors based on FET platforms working at low temperature are investigated. Several kinds of sensing materials are applied to FET platforms, including Polyvinyl alcohol (PVA) polymer, polyethylenimine (PEI) coated single-walled carbon nanotubes (SWNT) random network, and inorganic Na+ ionic conducting material. All kinds of the sensing material are deposited on the FET platform by using inkjet printing process. The basic electrical and CO2 sensing properties of these sensors are measured. The sensing mechanisms are also explained and modeled. PVA and PEI coated SWNT CO2 sensors are found to be able to detect CO2 at room temperature (about 25ºC) with the help of water vapor. The sensor with Na+ ionic conducting material can detect CO2 at 160ºC. all the sensors proposed in this work have much relative lower working temperature compared to typical CO2 sensors. The FET platform makes the sensor compatible with Si CMOS technology. A floating gate is adopted in the FET component which makes the calibration of the sensor very convenient. By comparison, the sensor with Na+ ionic conducting material has the most stable sensing behaviors without the requirement of water vapor during the detection, and can be expected to be a promising candidate for low temperature CO2 detection.Chapter 1. Introduction 1 1.1 Study background 1 1.1.1 Carbon dioxide monitoring and controlling 1 1.1.2 Gas sensors based on FET platforms 12 1.2 Purpose of research 16 1.3 Dissertation outline 17 Chapter 2. Device structure and fabrication 18 2.1 FET platform structure and fabrication 18 2.2 Sensing materials deposition 23 2.2.1 Organic polymer based sensing material 23 2.2.2 Carbon based sensing material 26 2.2.3 Sodium ionic conducting sensing material 29 2.3 Gas sensing measurement system 34 Chapter 3. Measurement results 37 3.1 PVA CO2 sensor 37 3.2 PEI-SWNT CO2 sensor 43 3.3 Na+ ionic conducting CO2 sensor 53 3.3.1 APTES SAM ion-blocking layer 54 3.3.2 Gas sensing performance 63 3.3.3 Programming of the FET sensor platform 65 Chapter 4. Device sensing mechanism 69 4.1 Sensing mechanism of PEI-SWNT sensor 69 4.2 Sensing mechanism of the sensor based on Na+ conducting material 76 Chapter 5. Conclusion 82 Bibliography 84 Abstract in Korean 91 List of Publications 93Docto

A High-Bandwidth, Spectrally Broad Photodetector Based on Optically-Induced Seebeck Effect

In this thesis, we engineered a fast response high bandwidth self-powered infrared photodetector based on optically induced Seebeck effect in Cd3As2 operating at room temperature. The metal-semimetal-metal device was subject to transient photo-response tests using high-frequency lock-in modulation techniques. Our photodetector demonstrates a Seebeck voltage under the off-center illumination of a laser with the wavelength of 1064 nm, due to a temperature gradient. The photocurrent is readily registered at a modulation frequency of 6 kHz and further analysis indicates the sensor intrinsic bandwidth is predicted to approach the terahertz range. The responsivity of the sensor is 0.27 mA/W at room temperature and the photocurrent is found to be dependent on the modulation frequency and the optical power. Our study reveals that Cd3As2 is a promising candidate for a fast response, high bandwidth spectrally broad device applications in optoelectronics