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:
- Cathode is, where electrons enter in the system.
- 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
asked Nov 26 at 23:12
user1306133
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up vote
2
down vote
favorite
When I learned, what the anode and the cathode are, there were two definitions corresponding to each other:
- Cathode is, where electrons enter in the system.
- 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
asked Nov 26 at 23:12
user1306133
132
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.
– Hearth
Nov 26 at 23:26
1
Possible duplicate of What is the definition of "cathode"?
– Jasen
Nov 27 at 6:00
add a comment |
up vote
2
down vote
favorite
up vote
2
down vote
favorite
When I learned, what the anode and the cathode are, there were two definitions corresponding to each other:
- Cathode is, where electrons enter in the system.
- 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
asked Nov 26 at 23:12
user1306133
132
When I learned, what the anode and the cathode are, there were two definitions corresponding to each other:
- Cathode is, where electrons enter in the system.
- 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
diodes
asked Nov 26 at 23:12
user1306133
132
asked Nov 26 at 23:12
user1306133
132
asked Nov 26 at 23:12
user1306133
132
asked Nov 26 at 23:12
user1306133
132
asked Nov 26 at 23:12
user1306133
132
132
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.
– Hearth
Nov 26 at 23:26
1
Possible duplicate of What is the definition of "cathode"?
– Jasen
Nov 27 at 6:00
add a comment |
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.
– Hearth
Nov 26 at 23:26
1
Possible duplicate of What is the definition of "cathode"?
– Jasen
Nov 27 at 6:00
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.
– Hearth
Nov 26 at 23:26
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.
– Hearth
Nov 26 at 23:26
1
1
Possible duplicate of What is the definition of "cathode"?
– Jasen
Nov 27 at 6:00
Possible duplicate of What is the definition of "cathode"?
– Jasen
Nov 27 at 6:00
add a comment |
2 Answers
2
active
oldest
votes
up vote
4
down vote
accepted
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.
answered Nov 26 at 23:45
Evan
1,974414
add a comment |
up vote
3
down vote
This is a diode:
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.
edited Nov 27 at 0:57
Edgar Brown
2,557320
answered Nov 27 at 0:07
τεκ
3,36611116
add a comment |
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
4
down vote
accepted
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.
answered Nov 26 at 23:45
Evan
1,974414
add a comment |
up vote
4
down vote
accepted
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.
answered Nov 26 at 23:45
Evan
1,974414
add a comment |
up vote
4
down vote
accepted
up vote
4
down vote
accepted
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.
answered Nov 26 at 23:45
Evan
1,974414
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.
answered Nov 26 at 23:45
Evan
1,974414
edited Nov 26 at 23:54
answered Nov 26 at 23:45
Evan
1,974414
answered Nov 26 at 23:45
Evan
1,974414
answered Nov 26 at 23:45
Evan
1,974414
1,974414
add a comment |
add a comment |
up vote
3
down vote
This is a diode:
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.
edited Nov 27 at 0:57
Edgar Brown
2,557320
answered Nov 27 at 0:07
τεκ
3,36611116
add a comment |
up vote
3
down vote
This is a diode:
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.
edited Nov 27 at 0:57
Edgar Brown
2,557320
answered Nov 27 at 0:07
τεκ
3,36611116
add a comment |
up vote
3
down vote
up vote
3
down vote
This is a diode:
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.
edited Nov 27 at 0:57
Edgar Brown
2,557320
answered Nov 27 at 0:07
τεκ
3,36611116
This is a diode:
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.
edited Nov 27 at 0:57
Edgar Brown
2,557320
answered Nov 27 at 0:07
τεκ
3,36611116
edited Nov 27 at 0:57
Edgar Brown
2,557320
edited Nov 27 at 0:57
Edgar Brown
2,557320
edited Nov 27 at 0:57
Edgar Brown
2,557320
2,557320
answered Nov 27 at 0:07
τεκ
3,36611116
answered Nov 27 at 0:07
τεκ
3,36611116
answered Nov 27 at 0:07
τεκ
3,36611116
3,36611116
add a comment |
add a comment |
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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.
– Hearth
Nov 26 at 23:26
1
Possible duplicate of What is the definition of "cathode"?
– Jasen
Nov 27 at 6:00