35 Questions 40 Answers 0 Followers
Questions related from Muhammad Farooq Saleem
what factors affect an epitaxial film's lattice matching and dislocation densities? Are there any possible ways to reduce lattice mismatch and dislocations in various deposition techniques?
11 November 2019 9,440 3 View
what is the difference between fluorescence and luminescence background in Raman spectra? What kind of materials give fluorescence background and what kind of materials give luminescence background?
07 July 2019 2,064 2 View
Cu2O and CuO are direct and indirect band gap materials respectively. We deposited a film that shows the Raman signatures of both CuO and Cu2O, what will be their band gap, direct or indirect?
06 June 2019 3,306 3 View
Sometimes, we can observe the IR-active and Raman-inactive modes in Raman spectra. What are the reasons behind the Raman activity of such modes?
05 May 2019 7,472 5 View
I have CVD graphene transferred to substrates. I am interested in p and n-doping of graphene. Are there any simple, easy and controllable methods of doping graphene films?
05 May 2019 1,342 9 View
We tried two different temperature dependent Raman set ups for our study. Every time we do temperature dependent Raman spectroscopy for a sample, the Raman signal is lost or quenched at some...
05 May 2019 3,846 8 View
I want to observe the surface of a sample in situ at different temperatures. Is it possible to take surface images at a particular temperature (mainly cryogenic temperatures)? If not, what in situ...
04 April 2019 5,247 11 View
We have a pulsed laser source, and I have fabricated graphene based photodetectors, I want to study the IV characteristics and photoresponse of the devices. We don;t have a power meter, we have a...
04 April 2019 2,977 5 View
what are the most temperature sensitive materials? Are there any materials that respond quickly to the abrupt temperature variations? I am interested in thin films mainly. I want find some...
04 April 2019 8,619 3 View
Its a photodetector.
04 April 2019 9,771 5 View
On a keithley source meters, the four connections are availabe, sense hi, sense lo, force hi and force lo. I want to know the difference between them.
03 March 2019 4,079 4 View
Is graphene prone to oxidation and water absorption in open air? Does graphene's quality degrade? how does oxidation and water adsorption affect it properties? can oxygen chemically adsorb on...
12 December 2018 5,609 0 View
I have bought CNTs from a supplier who gave us CNTs in alcohol. I want to do the Raman analysis of these CNTs. Can someone please suggest me the sample preparation steps? I tried to spread these...
12 December 2018 2,917 2 View
What are the key points on writing a project to get funding? Not all the times we have an excellent research idea, but professors emphasize their postdocs on submitting research projects to get...
10 October 2018 7,726 0 View
I have fabricated a back gated device. I want to use a laser light to measure the IV characteristics under laser illumination. For this purpose, I have to illuminate the 5 um channel of my device....
10 October 2018 2,154 4 View
we use XPS (X-ray photoelectron spectroscopy) to get the information about the hybridization (sp2/sp3) and binding energy of a material at room temperature. What techniques can be used to probe a...
09 September 2018 1,272 3 View
I deposited a thin layer of metal on Graphene in channel region and the IV characteristics changed. I don't exactly understand what happened. Also the leakage current increased to mA. But leakage...
09 September 2018 8,065 0 View
I have found some papers where they say that Raman G peak positions can be used to determine the thermal expansion coefficient of Graphene. The process they suggest is as follows: X= w-w0 x=...
08 August 2018 4,965 1 View
Let's say, we have sp2 carbon (Graphene) and it transform to sp3, somehow. what are the possible ways that can contribute to this transition? The question is most basic, "how the transitions occur...
08 August 2018 2,721 3 View
CVD grahene based devices have been fabricated which often show a Dirac point near 30V or even higher. There is no Dirac point for some the devices/ The question is what chemical processing can...
07 July 2018 5,980 0 View
What are the possible ways of subtracting substrate signal from epitaxial graphene. The SiC substrate signal dominates in Raman spectra making the Raman analysis difficult.
06 June 2018 3,184 3 View
Graphene based devices have to be washed with acetone, DMF, and water. How can we avoid/reduce oxidation and water absorption? How can we maintain the intrinsic properties of graphene throughout...
05 May 2018 5,237 4 View
I fabricate GFETs on SiO2. the Devices have to be washed with acetone DMF and water for cleaning after lithography and all the fabrication process is over. Finally, to dry the device and remove...
05 May 2018 2,572 5 View
I have epitaxial Graphene samples. I have the Raman spectra of the two faces of the sample. I’m wandering how to determi the SiC crystal face and phase using Raman spectroscopy.
04 April 2018 8,454 0 View
My CVD grown Garphene intrinsically shows p-type behavior as indicated by transfer curves obtained. I am not sure what exactly is causing its p-type doping. I remove PMMA by using dichloromethane,...
04 April 2018 6,291 4 View
I am looking for a colored version of a patent. Its black and white version is blur. Please tell me where I can find a colored or an improved copy of a patent? Thanks
04 April 2018 4,494 3 View
I have fabricated a back-gated GFET (Graphene field effect transistor ). I have a four probe station. I want to measure transfer curves for my device. I am not sure if I have connected the four...
01 January 2018 1,459 4 View
I found some interesting papers published in Nature Nanotechnology, Where can we find the "Methods"?? There are no experimental details, with only a statement that the "Methods and any associated...
12 December 2017 4,821 6 View
What if only a broad 2D peak is present with G peak of Graphene missing in Raman spectrum? what is it if its not Graphene?
12 December 2017 2,670 6 View
What if 2D peak is missing with G and D peak present in the Raman spectrum of Graphene? I am trying to growth Graphene, but I got G and D peaks in the spectrum. 2D peak is missing. What exactly is it?
12 December 2017 1,682 15 View
why acid doesn't dissolve Graphene when using PMMA assisted transfer process? usually Graphene grows on both sides of the metal substrates. Which layer do we obtain during the transfer process?...
11 November 2017 5,043 2 View
Graphene can be peeled off from HOPG, Why can't it be peeled off from CVD Grown Graphene on metallic substrates?
11 November 2017 605 3 View
In literature, CuO is reported to be n-type and sometimes p-type semiconductor. what exactly is it?
08 August 2016 5,848 5 View
How can we convert the ASCII files to Jade MDI readable files. My MDI jade does not support ASCII files. It supports files with extension ".raw". But my data is in the form of ASCII and I dont...
05 May 2016 3,874 1 View
somebody please tell me the band gap of CdS at liquid nitrogen temperature (83 K/ -190 C). Any reference??
05 May 2016 258 1 View
