Combining the electronic properties of graphene(1,2) and molybdenum disulphide (MoS2)(3-6) in hybrid heterostructures offers the possibility to create devices with various functionalities. Electronic logic and memory devices have already been constructed from graphene-MoS2 hybrids(7,8), but they do not make use of the photosensitivity of MoS2, which arises from its optical-range bandgap(9). Here, we demonstrate that graphene-on-MoS2 binary heterostructures display remarkable dual optoelectronic functionality, including highly sensitive photodetection and gate-tunable persistent photoconductivity. The responsivity of the hybrids was found to be nearly 1 x 10(10) A W-1 at 130 K and 5 x 10(8) A W-1 at room temperature, making them the most sensitive graphene-based photodetectors. When subjected to time-dependent photoillumination, the hybrids could also function as a rewritable optoelectronic switch or memory, where the persistent state shows almost no relaxation or decay within experimental timescales, indicating near-perfect charge retention. These effects can be quantitatively explained by gate-tunable charge exchange between the graphene and MoS2 layers, and may lead to new graphene-based optoelectronic devices that are naturally scalable for large-area applications at room temperature.

Graphene-MoS2 hybrid structures for multifunctional photoresponsive memory devices

Perovskite‐Based Phototransistors and Hybrid Photodetectors

Optoelectronic synapses integrating synaptic and optical-sensing functions exhibit large advantages in neuromorphic computing for visual information processing and complex learning, recognition, and memory in an energy-efficient way. However, electric stimulation is still essential for existing optoelectronic synapses to realize bidirectional weight-updating, restricting the processing speed, bandwidth, and integration density of the devices. Herein, a two-terminal optical synapse based on a wafer-scale pyrenyl graphdiyne/graphene/PbS quantum dot heterostructure is proposed that can emulate both the excitatory and inhibitory synaptic behaviors in an optical pathway. The simple device architecture and low-dimensional features of the heterostructure endow the optical synapse with robust flexibility for wearable electronics. This optical synapse features a linear and symmetric conductance-update trajectory with numerous conductance states and low noise, which facilitates the demonstration of accurate and effective pattern recognition with a strong fault-tolerant capability even at bending states. A series of logic functions and associative learning capabilities have been demonstrated by the optical synapses in optical pathways, significantly enhancing the information processing capability for neuromorphic computing. Moreover, an integrated visible information sensing memory processing system based on the optical synapse array is constructed to perform real-time detection, in situ image memorization, and distinction tasks. This work is an important step toward the development of optogenetics-inspired neuromorphic computing and adaptive parallel processing networks for wearable electronics.

Large-Scale and Flexible Optical Synapses for Neuromorphic Computing and Integrated Visible Information Sensing Memory Processing.

With the advancement in molecular biology, several metabolic and physiological processes have been elucidated at molecular levels discovering the involvement of different genes. Since the advent of plant transformation 33 years ago, use of plant transformation techniques sparked an interest in fundamental and applied research leading to the development of biological and physical methods of foreign DNA delivery into 130 plant species. Modern molecular biology tools have developed rich gene sources which are waiting to be transformed into plant species. But unavailability of efficient transformation methods is a major hurdle to expedite the delivery of these genes into plants. Ever-expanding available gene pools in the era of third generation transgenic plants stressing the delivery of multiple genes for different traits; development and application of new transformation methods is the big need of the time to meet the future challenges for plant improvement. In recent years, silicon-carbide whiskers have proven valuable and effective alternative in which silicon carbide fibers are mixed with plant cells and plasmid DNA, followed by vortexing/oscillation. Cell penetration appears to occur thus whiskers function as numerous fine needles, facilitating DNA entry into cells during the mixing process. This technique is simple, easy and an inexpensive transformation method to deliver the DNA into monocot and dicot plant species. Whiskers, cells and plasmid DNA are combined in a small tube and mixed on a vortex or oscillating mixer. In this chapter we will discuss the use of silicon carbide fibers/whiskers to transform and produce different transgenic plants. This chapter will help the reader to know about emerging applications of silicon carbide and other fibers in the delivery of foreign DNA into plants, and critical parameters affecting DNA delivery efficiency will also be discussed.

Properties and Applications of Silicon Carbide

We report the spectral response and slow decay of the steady-state photoconductivity in poly(p-phenylenevinylene) (PPV) films. The spectral response of the photoconductivity is in good agreement with that calculated from the absorption data with the assumption of rapid recombination at the surface of the film; the results indicate direct photogeneration of free charge carriers via an interband transition. The photoconductivity is, therefore, consistent with a description of the electronic structure of PPV in terms of a semiconductor band model (rather than an exciton model). The very slow stretched-exponential relaxation of the photoinduced conductivity is reminiscent of the persistent photoconductivity observed in inorganic semiconductors. By assuming that the photocurrent is carried predominantly by mobile polarons near the surface, one can construct a model for the persistent photoconductivity in which the recombination of long-lived bipolarons is inhibited in the bulk where bipolarons have a lower free energy than polarons. The persistent photoconductivity, therefore, is caused by the slow dispersive diffusion of photogenerated bipolarons to the surface where they dissociate into polarons and where both polaron transport and recombination occur.

/pdf/persistent-photoconductivity-in-poly-p-phenylenevinylene-3wd3uwu5bo.pdf

Persistent photoconductivity in poly(p-phenylenevinylene): Spectral response and slow relaxation.

Kinetic studies of the decay of persistent photoconductivity can decide between competing interpretations This paper is concerned with the temporal decay of excess conductivity after illumination for low temperatures and spatial carrier separation The initial decay is rapid since closely spaced carriers recombine; later decay is retarded Analytic expressions are derived for various trap profiles Epitaxial GaAs and interfaces of Al/sub x/Ga/sub 1-x/As-GaAs heterostructures are investigated; the results agree with theory, which predicts a decay essentially logarithmic in time

Decay kinetics of persistent photoconductivity in semiconductors

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

D.E. Theodorou

Author Tools

Chat about Author

Papers

Decay kinetics of persistent photoconductivity in semiconductors