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Questions related from Amr Hessein
If I know the band gap if a certain semiconductor, and I would like to calculate the value of the absorption coefficient numerically using the following equation: how to determine the values of...
02 February 2017 3,453 1 View
I want to make modeling and simulation for thin film solar cell and thin film interfaces composed from nano structured materials. But I don't have any experience in that field. So any one can...
11 November 2016 2,382 43 View
I want to get reduced graphene oxide powder, So, Is there is any method to prevent the re- stacking of graphene sheets after the reduction of graphene oxide?
03 March 2016 6,118 5 View
I had made many Au Counter electrodes using ion sputtering for different times. But the problem is these counter electrodes are not mechanically stable on the FTO substrate and peeled of with the...
03 March 2016 2,812 2 View
Can any one tell me how to differentiate experimentallybetween direct allowed and direct forbidden transitions in direct band gap semiconductors. is there is a table or a database shows the...
02 February 2016 761 7 View
I made my counter electrode from nickel sulfide- Graphene composite on FTO substrate by using PVDF as a binder. But when the QDSSCs assembled by using polysulfide electrolyte, the counter...
10 October 2015 3,806 3 View
my counter electrode for the quantum dot sensitized solar cell made from nickel sulfide. In the presence of polysulfide electrolyte, the counter electrode dissolving and contaminating the working...
10 October 2015 417 3 View
I want to use a Ultra-high-performance lamp as a light source in measuring the J-V curve of solar cell. But I want to know first the full spectrum of this lamp. does it emits in the UV range or...
05 May 2015 8,549 5 View
I need to get a light source that simulate the sunlight in order to test my samples. Can I use "400 W metal halide lamp" or " Halogen lamp" is better?
04 April 2015 3,239 14 View
I need to measure the J-V curve for solar cell using Princeton Versastat 4 potentiostat. How can I connect the terminals of the potentiostat?
04 April 2015 5,761 11 View
the most Raman spectrometers use LASER wavelengths of 533 and 633 during characterizing Graphene. When a LASER of wavelength 785 nm is used the D & G peaks in the spectrum are greatly shifted...
04 April 2015 2,568 9 View
I need to roughly estimate the electric conductivity of powder samples such as graphite and graphene. The problem is the sample quantities is so small and can not be compressed in pellets of desks.
04 April 2015 3,859 6 View
I am trying to calculate the magnitude of warburg impedance (Zw) from its coefficient (Aw) using the equation: Zw= 2^0.5(Aw)/w^0.5 so, I want to how to find the value of angular frequency (w) to...
02 February 2015 619 4 View
I need to make optimization for doctor blade technique used to deposit TiO2 mesoporous film used in sensitized solar cell. The optimization process I would like to do includes 1- constant...
11 November 2014 9,587 7 View
Alternative to the unstable sodium sulfide + sulfur in water + methanol one?
10 October 2014 2,611 1 View
I would like to know what the active area of DSSCs is? Is it the total area of the working electrode or do the researchers use a "photomask" with a specified area to define the active area during...
10 October 2014 7,866 6 View
I working on developing a counter electrode of sensitized solar cell based on graphene. And I need to perform EIS of these electrodes. In the literature, the authors perform EIS of cells consist...
10 October 2014 8,106 11 View
I need to use Filmetrics F20 (http://www.filmetrics.com/thicknessmeasurement/f20) to measure the thickness of tio2 layer coated on FTO glass used as a working electrode in dye sensitized solar...
10 October 2014 8,562 3 View
Must be alternative to the unstable sodium sulfide + sulfur in water + methanol method.
10 October 2014 5,081 1 View
I need someone to tell me what are the cost effective alternatives for sun simulators as a light source. My work is in the photovoltaics area and I need to characterize my solar cell samples.
09 September 2014 5,350 14 View
Can any one show me the main differences between "potentiostat" and "electro- chemical working station"
09 September 2014 4,370 0 View
I need to measure the thin film thickness of mesoporous TiO2 layer using "filmetrics F20 thin film analyzer" but I want to know the refractive index of TiO2 P25
09 September 2014 1,736 5 View
To whom work in quantum dot sensitized solar cell. I prepare polysulfide electrolyte with concentration 1M Na2S and 1M S in distilled water. My problem is after some time I found a green...
08 August 2014 6,823 2 View
The resistance value is variable by changing the current value of the same measured point.
03 March 2014 9,218 8 View
