Відео

I guess you are referring to a battery. Although I hesitate to use positive and negative for the electrodes of the diode, but, as some people do, it is the opposite of a battery which is a source. In diodes anode is the electrode that current enters the diode and cathode is the electrode that current leaves the diode. In batteries, when supplying is the opposite, current come out from the positive side. Of course, when the battery is charging, current enters the positive side.

Glad it helped!

You're very welcome!

I am afraid there is no simple answer to this question. The potential barrier cannot found from the IV characteristics. It depends on the doping concentration of the semiconductors. These parameters are embedded in the reverse saturation current in the diode equation. Some researchers have used modelling techniques to estimate the potential barrier height. For example, this: aip.scitation.org/doi/10.1063/1.4789989 (I am not sure if you could have access to the paper, unless you are a student or work in a place that have subscription to the journal). It is possible to find the series resistance by modelling too, but both of them need advanced techniques.

Thank you. I am glad that you found it helpful.

Please see my video Simple Diode Calculations 1. Ideal Diode (ua-cam.com/video/s7v69QXKMdU/v-deo.html)

Most welcome

You're welcome

Sure. It has been a very busy time. I hope I can make more videos very soon.

Thank you for watching. It is not log or ln, but the scale is logarithmic. Even if it was log, It didn't make any change on the slope. The ln of a value is 2.3 times the log of that value. It just changes the scale of y axis and doesn't change the shape of the graph. I hope that you find the explanation helpful.

@@drnasersedghi Thank you sir. Your explanation is very helpful. I love your videos for the brevity and clarity of explanations. This is what students need. Would you mind if I ask you a one more question? I am interested in why the ideality factor of a solar cell in the low voltage region can be less than 1. This is described in work: 10.1155/2017/8479487 (figure 5). I also discovered this when I prototyped a porous silicon solar cell in the lab. You can see IV curve obtained by me here: ibb[dot]co[slash]6nyrQFS. Here I had n=0,35 in the voltage range 0-0,025 V.

@@physmath9386 Thank you again for your interest in my video. The ideality factor is defined based on the Shockley diode equation. However, there might be some other conduction mechanisms which can deviate the diode IV characteristics from Shockley equation. These are usually modelled as series resistance and shunt resistance. At very small voltages, the shunt resistance is dominant and the diode does not follow Shockley equation. If we calculate the ideality factor in this region, we find a value less than one, but its cause is not the ideality factor in the diode equation.

@@nasersedghi Thank you again sir! Your videos and answers are very helpful for me.

The videos provided here are for an elementary electronics course. You can find the recombination in the depletion layer and high carrier injection in more advanced books on electronic devices.

The ideality factor can be calculated from the semi-logarithmic plot of normalized current versus normalized voltage shown in minutes 2:19 to 3:05. The slope of the curve equals one divided to the ideality factor. This is how the researchers calculate the indeality factor for new devices.

@@drnasersedghi Thanks again

@@rajdeep7124 You are very welcome.

You are welcome. You can find the basic diode theory and applications nearly in any electronics textbook. My favourite is Microelectronics by Jacob Millman, however, it is many years that it has not been reprinted (I think the last edition was 2001). Another good textbook is Microelectronics by Sedra. I am sure that there are many good new textbooks.

I have already replied to Mr Rana. For the interest of the others, if you plot the IV characteristics with a logarithmic scale for current (shown in this video), the slope of the curve is proportional to one divided by ideality factor, from which you can find the ideality factor. This is the method which is always used in scientific research on new devices.

Thank you.