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Can I use the analogy of combination of two batteries to get the potential difference between two points(by applying Kirchhoff's law) in case ,if a pn junction diode is used in the place of other battery?

Consider a simple case shown in figure,there in situation 1 potential due to two batteries are added up and in situation two the the second battery is replaced by a diode in forward bias, if I apply Kirchhoff's law then moving from point AI am gaining a potential of 2V and a gain in potential V(s) in diode . In doing so what is the basic mistake I am doing?
As per Wikipedia in forward bias net voltage = 2V-Vs, but if I follow the above approach iam getting 2V+Vs. I think about this a lot but could not get any idea.

schematic representation of my question

JM97
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1 Answers1

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See this image from http://www.allaboutcircuits.com/textbook/semiconductors/chpt-2/the-p-n-junction/:

P-N junction

By looking at graph shown, we can say that in forward bias, PN junction is working as passive device (V/I > 0). So, it causes a voltage drop in this case. Thus, net voltage will be 2V-Vs.

When we talk about reversed bias, then net voltage will be 2V+Vs.

another 'Homo sapien'
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