In solar PV panel, P-N junction diode is used as solar PV cell which absorbs the light and convert light into electricity. But normal diode can not absorbs the light.
What is the structural difference between normal diode and Solar PV diode?
The solar cell is a pn-junction diode optimized to convert the incident solar radiation to electrical energy. Like wise every diode is optimized for its specific application such as rectifier diodes and zener diodes.
The major difference, however . is the metallization of the two electrodes, the anode and the cathode.
The back side of the solar cell which is normally the anode is completely metallized while the front side electrode is partially metallized in form of metal fingers and buss bars to allow light to pass to the active solar solar cell material and absorbed in the material to generate the photocurrent and at the same time collecting the photocurrent by the metal grid to access electrically the front electrode.
The other main difference is in the doping of the substrate material it is selected to optimize the the open circuit voltage while collecting an appreciable part of the incident radiation by adjusting its thicness. The optimum doping concentration fore silicon is about 10^17/cm^3 and the thicness is about 250 micrometer.
The normal diode is fully metallised from both sides an therefore it is opaque for light.
The course in this link may be useful to you:https://www.researchgate.net/publication/236002879_A_course_on_photo-voltaic_array_systems
The solar cell is a pn-junction diode optimized to convert the incident solar radiation to electrical energy. Like wise every diode is optimized for its specific application such as rectifier diodes and zener diodes.
The major difference, however . is the metallization of the two electrodes, the anode and the cathode.
The back side of the solar cell which is normally the anode is completely metallized while the front side electrode is partially metallized in form of metal fingers and buss bars to allow light to pass to the active solar solar cell material and absorbed in the material to generate the photocurrent and at the same time collecting the photocurrent by the metal grid to access electrically the front electrode.
The other main difference is in the doping of the substrate material it is selected to optimize the the open circuit voltage while collecting an appreciable part of the incident radiation by adjusting its thicness. The optimum doping concentration fore silicon is about 10^17/cm^3 and the thicness is about 250 micrometer.
The normal diode is fully metallised from both sides an therefore it is opaque for light.
The course in this link may be useful to you:https://www.researchgate.net/publication/236002879_A_course_on_photo-voltaic_array_systems
Prof. Zekry has detailed the differences very well. I also thank him for the book, which will serve as a bonus for me.
I will add a few points as my two-penny bit:
There is a difference in dimensions between the two layers. If we go by the typical configuration (anode back) that Prof. Zekry mentions, then you will find that the positive doped part is a thick layer, on which the "cathode top" is a thin one (just a few microns).
There is a fundamental difference of phenomenon. In the same typical configuration, the negatively doped part receives the irradiation, the electrons are excited and move to the positive layer, and that is how the "PV show begins" ! So the usual diffusion current due to minority carriers that happens in a diode is not what we are fundamentally banking on for the PV show.
The diffusion current due to minority carriers part is by no means missing in the PV cell (as you may guess, it can not be, since you do have a junction between the layers, after all !!). It coexists with the PV current generation as what goes by the name of diode effect - almost an undesirable parasitic effect in this case !! Most basic books cover this as part of what commonly goes by the name PV cell equivalent circuit. I am sure Prof. Zekry's book does so too.
Both are silicon diodes but the requirements are different..a photo diode has small area of silicon and hence it generates less amount of power.Whereas it is quite different in solar diode.It has large area of silicon and hence generates considerable amount of power.