Kebbab Zoubir

32 Questions 34 Answers 0 Followers

Questions related from Kebbab Zoubir

What is the best method for tracking the sun position, is-it by solar position calculation along the day of the year or by other method?

In solar energy application, often we should know the sun position at each instant. With the sun position calculation, I think we can establish a database for this purpose. Then we can use-it for...

01 January 2015 7,318 12 View

In multilayer PV solar cells, how can I choose the materials (gap and contact type) in order to increase efficiency ?

When the PV solar cell is used in a multi layer form, the goal is to benefit of a large interval of solar radiations. I think that the gap and the contact of different layers must have certain...

01 January 2015 3,640 4 View

There are much old films which are colored later. How we proceed to retrieve the suitable color for original picture ?

There are much old films which are colored later. The obtained result seems to be satisfactory. The colors can be different from the originals but it is sufficient for mistaking the human eyes....

12 December 2014 8,596 1 View

The IR radiations are harmful for the performances of photovoltaic solar cells; how is-it possible to eliminate these kind of radiations ?

Among the parameters which decrease the efficiency of the photovoltaic solar cells, we can note the solar IR radiations. This kind of radiation increases the temperature and then disturbs often...

12 December 2014 502 17 View

Why we use the term of "optical constants" of a material in spite of their variations ? is-it by misnomer ?

Optical constants as well as the gap, represent the signing of a material. They must be specific for this material. However, optical constants depend of the size of the crystallites which form the...

12 December 2014 5,787 3 View

Can we predict barrier potential in a contact metal-semiconductor or semiconductor-semiconductor using a theoretical approach ?

From band structure obtained with an existing calculation method , can we reach the result relating to the contact barrier between two materials ?

12 December 2014 5,540 13 View

What is the energy value of a phonon generally measured in an indirect transition?

Is it possible to obtain a phonon energy of about 425 meV, or is it an indirect transition assisted with more than one phonon?

12 December 2014 6,316 1 View

Is it possible to obtain a natural colored image using electron microscopy or ecography ?

Until today, a good colored image is obtained using exclusively light. Electron microscope uses electrons and echograph uses ultrason. That gives only gray images.

11 November 2014 7,812 11 View

What kind of chemical products are generally used in order to target a given thin film by the CBD technique?

We can take the case of WO3 or CdTe as example

09 September 2014 9,257 2 View

What is the best chemical solution which can be used to obtain tungsten oxide in the framework of chemical bath deposition (CBD)?

Especially to target the WO3 oxide.

03 March 2014 2,892 2 View

Why does the energy gap of a quantum dot vary with its dimension?

Because of the gap of each material represents a signature of this material, why is it not the case for a quantum dot made with the given material.

02 February 2014 8,426 3 View

Can someone suggest a free phonon software that can be connected to wien2k code?

The desired software must be similar if possible to the commercial code entitled : Phonon.

02 February 2014 9,421 2 View

Can one determine the potential barrier in semiconductor-semiconductor contact using a calculated band structure for each material?

The band structure is easy to determine using ab-initio calculation (e.g Wien2k code). How can we determine the potential barrier obtained by the given materials from the band structure of each...

12 December 2013 5,994 6 View

Can anyone tell me how to choose the precursors in the chemical bath deposition process (CBD)?

Please, give me some example for obtaining semiconductors compound (CdTe, PbS, ZnO, etc.)

12 December 2013 6,066 1 View

What is the best dispersion function which can describe an absorber thin film?

In the scientific literature, we can read many dispersion functions which are suitable for a certain type of thin film (Cauchy, Sellmeier, Lorentz, Drude...). My goal is how to describe the...

09 September 2013 8,143 2 View

How can one map a country in term of solar radiation using calculation procedure?

How to resolve the existence of microclimates in the country subject of these calculations? Is there any model for this kind of problems ?

08 August 2013 6,587 5 View

Which semiconductor should be present in terms of physical properties in order to use it in solar cell applications?

What are the most interesting properties of semiconductors (gap, etc.), which allows us their utilization in solar cells?

08 August 2013 516 7 View

Is there any difference between optical and electrical conductivity? If yes, how can one explain this difference physically?

The same question can be asked also in the case of electrical gap and optical gap.

07 July 2013 4,868 18 View

Can anyone explain the SILAR process principle and what kind of material we can obtain?

This question is asked in order to manufacture thin solid film on a glass substrate. I wish also to have responses on the principal precursors used in this technique.

06 June 2013 8,171 5 View

Help for applying Kramers-Kronig inversion in the optical characterization especially from the measure of reflectivity.

The cauchy integral should be performed from zero to infinity. The measured interval is limited. How to complete the interval related to cauchy integral?

05 May 2013 2,290 6 View

Is there any method from which we can determine elastic coefficients or others constraints using XRD spectrum?

Is there any method for doing this previous work.

04 April 2013 4,027 4 View

DSSC - can it work successfully with solid electrolyte? If yes, what solid electrolyte can be used?

The most used electrolyte in DSSC applications is liquid. I think that solid electrolyte is more suitable for manufacturing of this kind of solar cells.

04 April 2013 6,982 3 View

TiO2 is often used in DSSC. Is there other materials which can replace this successfully?

What physical properties should have the material in order to replace TiO2 in the DSSC applications?

04 April 2013 2,492 7 View

From DOS (density of state) calculation, can we determine the type (n or p) of the studied semiconductor?

Density of state or band structure energy can be obtained using any theoretical approach, for example DFT. So, from these results, is it possible to determine the type (n or p) of a given...

04 April 2013 4,055 21 View

Are there any suitable software or method which can be used in the determination of LUMO HOMO energy levels?

Particularly in the determination of LUMO HOMO for dyes or similar products.

04 April 2013 2,011 8 View

When we make an optical polarisation, we act on electrical field. Why we cannot do the same on the magnetic field.

It is well known that light is an electromagnetic wave. Because of this, it presents two fields: (electric and magnetic) perpendiculars. therefore, if we act on one field the other should follow....

04 April 2013 5,293 24 View

Is there any free and satisfactory FDTD software ?

Of course, we would use it for our simulation applications.

04 April 2013 9,102 2 View

Which polymers can be used as conductive and transparent material?

I need any polymer that can be used as transparent electrode.

03 March 2013 2,592 4 View

Calculating solar rayonnement in a given locality: what formula do I take into account?

Formulae which match with local weather.

03 March 2013 3,096 3 View

What is the best model which can give us the optical constants of composite material using those of the constituent materials?

The composite is made from two or more constituent materials. If we know the optical constants of origin materials, is it possible to determine those of the composite ?

03 March 2013 4,552 3 View

Why do we continue to talk about optical constants even if we have a change (bulk to thin film); is there a misnomer ?

The optical constants should signify a specificity for the material. That should not vary when the form (bulk thin film) of the sample varies.

03 March 2013 2,495 3 View

how do I proceed to eliminate the substrate effect in an optical measurement of thin films.

Spectroscopy of thin films

03 March 2013 3,968 19 View