PiN diode - is the total junction voltage 0.7Volt or 1.4Volts

[Jedrzej ("Andrew") Szelc]

Hello,

I would be very grateful if someone out there could explain to me how
the proper PiN diode I-V characteristic should look like.

Is the total junction drop across the PiN junction 1.4Volts (due to
the interaction between the P+N and NN+ junctions) or is it just
0.7Volt?

I did some small research with regard to the above quesiton. From the
following two books:
1) Sorab k. Ghandi - "Semiconductor Power Devices" - ISBN:
0.47-02999-8
2) David J. Roulston - "Bipolar Semicondcutor Devices"

I have learnt that a proper PiN diode (P+NN+ junction operating under
forward bias) should have a total voltage drop across the PiN diode is
1.4Volts. From the books I know that the total voltage drop is
2*0.7Volts (P+N junction voltage and NN+ junction voltage, the latter
is related to the existence of the so called "retarding field").

Is 1.4Volts for a PiN diode really true?

I will appreciate any comments on that.

Kind Regards,
Andrew Szelc