Cathode Interpretation Contradiction











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When I learned, what the anode and the cathode are, there were two definitions corresponding to each other:




  1. Cathode is, where electrons enter in the system.

  2. Anode comes from the greek anodos meaning "going upwards", that is where current enters the system (that is the dirrection opposing to the flow of the electrons)


Now when I tried to understand the reverse biasedness of a photodiode, I struggled half an hour until I realized, that most of the sources I could find, refers the N-doped end of the diode a cathode, even if the current is now reverse.



Did I miss something? Why is that? Is there another interpretation for these notions?










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    The n-doped side of a diode is always called the cathode, and the p-doped side is always the anode. Someone else could give more detailed information than I.
    – Felthry
    3 hours ago















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When I learned, what the anode and the cathode are, there were two definitions corresponding to each other:




  1. Cathode is, where electrons enter in the system.

  2. Anode comes from the greek anodos meaning "going upwards", that is where current enters the system (that is the dirrection opposing to the flow of the electrons)


Now when I tried to understand the reverse biasedness of a photodiode, I struggled half an hour until I realized, that most of the sources I could find, refers the N-doped end of the diode a cathode, even if the current is now reverse.



Did I miss something? Why is that? Is there another interpretation for these notions?










share|improve this question







New contributor




user1306133 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
















  • 1




    The n-doped side of a diode is always called the cathode, and the p-doped side is always the anode. Someone else could give more detailed information than I.
    – Felthry
    3 hours ago













up vote
1
down vote

favorite









up vote
1
down vote

favorite











When I learned, what the anode and the cathode are, there were two definitions corresponding to each other:




  1. Cathode is, where electrons enter in the system.

  2. Anode comes from the greek anodos meaning "going upwards", that is where current enters the system (that is the dirrection opposing to the flow of the electrons)


Now when I tried to understand the reverse biasedness of a photodiode, I struggled half an hour until I realized, that most of the sources I could find, refers the N-doped end of the diode a cathode, even if the current is now reverse.



Did I miss something? Why is that? Is there another interpretation for these notions?










share|improve this question







New contributor




user1306133 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











When I learned, what the anode and the cathode are, there were two definitions corresponding to each other:




  1. Cathode is, where electrons enter in the system.

  2. Anode comes from the greek anodos meaning "going upwards", that is where current enters the system (that is the dirrection opposing to the flow of the electrons)


Now when I tried to understand the reverse biasedness of a photodiode, I struggled half an hour until I realized, that most of the sources I could find, refers the N-doped end of the diode a cathode, even if the current is now reverse.



Did I miss something? Why is that? Is there another interpretation for these notions?







diodes






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user1306133 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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user1306133 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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Check out our Code of Conduct.








  • 1




    The n-doped side of a diode is always called the cathode, and the p-doped side is always the anode. Someone else could give more detailed information than I.
    – Felthry
    3 hours ago














  • 1




    The n-doped side of a diode is always called the cathode, and the p-doped side is always the anode. Someone else could give more detailed information than I.
    – Felthry
    3 hours ago








1




1




The n-doped side of a diode is always called the cathode, and the p-doped side is always the anode. Someone else could give more detailed information than I.
– Felthry
3 hours ago




The n-doped side of a diode is always called the cathode, and the p-doped side is always the anode. Someone else could give more detailed information than I.
– Felthry
3 hours ago










2 Answers
2






active

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3
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There is an unfortunate discrepency in the history of the words.



In electrochemical devices such as batteries and electrolysis tanks anode and cathode are determined by the direction of ion/electron movement within the cell. Electrons and negative ions move through the electrolyte toward the anode while positive ions move toward the cathode. This means that when a battery is discharging vs. charging, the anode and cathode switch places. Technically an open circuit battery has no anode or cathode as no charges are moving.



In semiconductor diodes anode and cathode refer to the doping. N-doped is always the cathode and P-doped is always the anode regardless of the direction of current flow.



One more bit of confusing terminology: anions are species attracted to anodes, and therefore negatively charged. Cations are positive ions.






share|improve this answer






























    up vote
    1
    down vote













    This is a diode:



    diode tube



    Image From uv201.com



    It is a vacuum tube with two terminals (not counting the heater). Much like a triode is a three terminal vacuum tube.



    The cathode emits electrons by thermionic emission, and those electrons are only attracted to the anode if it is at a higher voltage, meaning it rectifies the current flowing through it.



    Fifty years later a semiconductor device with the same purpose was invented.






    share|improve this answer























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      2 Answers
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      active

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      2 Answers
      2






      active

      oldest

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      active

      oldest

      votes






      active

      oldest

      votes








      up vote
      3
      down vote













      There is an unfortunate discrepency in the history of the words.



      In electrochemical devices such as batteries and electrolysis tanks anode and cathode are determined by the direction of ion/electron movement within the cell. Electrons and negative ions move through the electrolyte toward the anode while positive ions move toward the cathode. This means that when a battery is discharging vs. charging, the anode and cathode switch places. Technically an open circuit battery has no anode or cathode as no charges are moving.



      In semiconductor diodes anode and cathode refer to the doping. N-doped is always the cathode and P-doped is always the anode regardless of the direction of current flow.



      One more bit of confusing terminology: anions are species attracted to anodes, and therefore negatively charged. Cations are positive ions.






      share|improve this answer



























        up vote
        3
        down vote













        There is an unfortunate discrepency in the history of the words.



        In electrochemical devices such as batteries and electrolysis tanks anode and cathode are determined by the direction of ion/electron movement within the cell. Electrons and negative ions move through the electrolyte toward the anode while positive ions move toward the cathode. This means that when a battery is discharging vs. charging, the anode and cathode switch places. Technically an open circuit battery has no anode or cathode as no charges are moving.



        In semiconductor diodes anode and cathode refer to the doping. N-doped is always the cathode and P-doped is always the anode regardless of the direction of current flow.



        One more bit of confusing terminology: anions are species attracted to anodes, and therefore negatively charged. Cations are positive ions.






        share|improve this answer

























          up vote
          3
          down vote










          up vote
          3
          down vote









          There is an unfortunate discrepency in the history of the words.



          In electrochemical devices such as batteries and electrolysis tanks anode and cathode are determined by the direction of ion/electron movement within the cell. Electrons and negative ions move through the electrolyte toward the anode while positive ions move toward the cathode. This means that when a battery is discharging vs. charging, the anode and cathode switch places. Technically an open circuit battery has no anode or cathode as no charges are moving.



          In semiconductor diodes anode and cathode refer to the doping. N-doped is always the cathode and P-doped is always the anode regardless of the direction of current flow.



          One more bit of confusing terminology: anions are species attracted to anodes, and therefore negatively charged. Cations are positive ions.






          share|improve this answer














          There is an unfortunate discrepency in the history of the words.



          In electrochemical devices such as batteries and electrolysis tanks anode and cathode are determined by the direction of ion/electron movement within the cell. Electrons and negative ions move through the electrolyte toward the anode while positive ions move toward the cathode. This means that when a battery is discharging vs. charging, the anode and cathode switch places. Technically an open circuit battery has no anode or cathode as no charges are moving.



          In semiconductor diodes anode and cathode refer to the doping. N-doped is always the cathode and P-doped is always the anode regardless of the direction of current flow.



          One more bit of confusing terminology: anions are species attracted to anodes, and therefore negatively charged. Cations are positive ions.







          share|improve this answer














          share|improve this answer



          share|improve this answer








          edited 3 hours ago

























          answered 3 hours ago









          Evan

          1,949414




          1,949414
























              up vote
              1
              down vote













              This is a diode:



              diode tube



              Image From uv201.com



              It is a vacuum tube with two terminals (not counting the heater). Much like a triode is a three terminal vacuum tube.



              The cathode emits electrons by thermionic emission, and those electrons are only attracted to the anode if it is at a higher voltage, meaning it rectifies the current flowing through it.



              Fifty years later a semiconductor device with the same purpose was invented.






              share|improve this answer



























                up vote
                1
                down vote













                This is a diode:



                diode tube



                Image From uv201.com



                It is a vacuum tube with two terminals (not counting the heater). Much like a triode is a three terminal vacuum tube.



                The cathode emits electrons by thermionic emission, and those electrons are only attracted to the anode if it is at a higher voltage, meaning it rectifies the current flowing through it.



                Fifty years later a semiconductor device with the same purpose was invented.






                share|improve this answer

























                  up vote
                  1
                  down vote










                  up vote
                  1
                  down vote









                  This is a diode:



                  diode tube



                  Image From uv201.com



                  It is a vacuum tube with two terminals (not counting the heater). Much like a triode is a three terminal vacuum tube.



                  The cathode emits electrons by thermionic emission, and those electrons are only attracted to the anode if it is at a higher voltage, meaning it rectifies the current flowing through it.



                  Fifty years later a semiconductor device with the same purpose was invented.






                  share|improve this answer














                  This is a diode:



                  diode tube



                  Image From uv201.com



                  It is a vacuum tube with two terminals (not counting the heater). Much like a triode is a three terminal vacuum tube.



                  The cathode emits electrons by thermionic emission, and those electrons are only attracted to the anode if it is at a higher voltage, meaning it rectifies the current flowing through it.



                  Fifty years later a semiconductor device with the same purpose was invented.







                  share|improve this answer














                  share|improve this answer



                  share|improve this answer








                  edited 1 hour ago









                  Edgar Brown

                  2,043118




                  2,043118










                  answered 2 hours ago









                  τεκ

                  3,31811116




                  3,31811116






















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