Raju Kumar

17 Questions 39 Answers 0 Followers

Questions related from Raju Kumar

What could be the best way to smooth the spectrum (image attached)?

An emission spectrum in IR wavelength region consists of interference fringes (after spectral correction). How do I smooth such spectra? When collected through fiber, absorption around 950 nm...

07 July 2019 4,574 13 View

Change of oxidation state of 'Cr' in Al2O3 during interaction with ionizing radiation?

Ruby (Al2O3 doped with Cr3+ ions), when exposed to ionizing radiation (for e.g. X-rays), emits luminescence. What is the mechanism that causes this 'Radio-luminescence? Does Cr3+ accept electrons...

08 August 2018 3,533 5 View

Electron trapping in a defect at low temperature (7 K)?

Does trapping of electrons in a defect (trap) depend on temperature (below room temperature)? If yes, what are the possible reasons? I see that, these electrons appear to be trapped more (as well...

07 July 2018 2,286 10 View

How do I correct spectra consisting fringes (possibly due to etalon effect)?

I have recorded PL spectra using CCD detector with the help of detection filter upon exciting the sample with a NIR laser. In these spectra, I see interference fringes (figure attached). I would...

02 February 2018 3,012 4 View

In which condition, circular orbital motion of a satellite changes to elliptical?

If something causes final orbital speed of the satellite to be decreased (final orbital speed < initial orbital speed), why its circular motion changes to elliptical motion? Assuming that the...

02 February 2018 9,113 9 View

How can the presence of intrinsic and extrinsic defects be distinguished in a material?

If a material is supposed to be consisting of either intrinsic or extrinsic (or both) defects, how do they affect the physical characteristics of that material? Further, how one can differentiate...

12 December 2017 2,527 13 View

What is the temperature effect on the PL resulting from an excited state (of an impurity) which lies in high or low density of CB tail states?

If an excited state is considered to be lying in either low or high density conduction band tail states, how the temperature will affect the PL emission from that state? Is above scene possible?...

11 November 2017 5,933 3 View

How to obtain Energy Levels of a doped element (unknown) in a host material theoretically?

How to determine energy levels theoretically in a material. A wide band gap material doped with impurities. Could it be a tool to cross check the results obtained experimentally?

11 November 2017 2,274 4 View

How to create an user defined function to fit thermal quenching equation in Origin ?

I am trying to fit a thermal quenching equation in the form of I=I0/(1+c*exp(-E/((1.38*10^(-23))*T))), to my data in origin software. I'm unable to create a function that runs and fits...

11 November 2017 6,247 10 View

How to generate a very narrow, collimated light (laser) beam?

Is there any limit for generating narrow beam? How do I generate a narrow beam of 5 micron beam size?

10 October 2017 6,318 4 View

How do I modify a fitting function (Gaussian or Bigaussian ) when peak positions in spectra keep changing with temperature?

Two peaks in my PL spectra keep shifting towards each other when temperature is taken from 7K to 295K and finally merge into one. I need to deconvolute them at each stage to have better...

09 September 2017 471 8 View

In which conditions, fluorescence are seen from first excited state and second excited state (may be also from higher states) simultaneously?

Which emission is more likely to occur or will have more intensity then? How can we justify this with selection rules? Any references and comments will be highly appreciated.

08 August 2017 4,976 19 View

Do I need to correct the PL spectra further when using cut-off filter(s) at the emission side?

I'm recording PL spectra with a CCD detector by putting a cut off filter in front of it (laser is used as an excitation source). There is an option, already available, for recording the spectra...

07 July 2017 782 4 View

How does p-n junction form in an Organic-Inorganic hybrid solar cell even in the presence of oxide layer between them?

SiO2 layer hepls PEDOT:PSS to make a good contact with Silicon. It has got a thickness of 2-3 nm. Then how a p-n junction will form if semiconductors are apart?

03 March 2016 6,049 4 View

What kind of silicon wafers (SSP or DSP) are required for carrier lifetime measurements?

any link?

02 February 2016 616 0 View

I would like to know about adhesion of PEDOT-PSS on c-Si? Whether the native oxide helps in adhesion?

Cite any publication if available please.

02 February 2016 7,872 1 View

Can we anneal PEDOT:PSS spincoated Si wafer further if it has already been given an initial heat treatment? What effect can be seen?

possible idea?

02 February 2016 4,288 0 View