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What is the effect of photodiode reverse bias voltage?
When reverse biased, current will only flow through the photodiode with incident light creating photocurrent. The reverse bias causes the potential across the depletion region to increase and the width of the depletion region to increase. This is ideal for creating a large area to absorb the maximum amount of photons.
What happens when photodiode is forward biased?
A forward bias reduces the strength of the potential barrier of the electric field across the potential, whereas a reverse bias strengthens the potential barrier. A forward bias has an anode voltage that is larger than the cathode voltage.
How a photodiode is biased for its use?
When a bias is applied to a photodiode, the current output can be controlled to provide thresholding, linear response, or nonlinear response. In particular, placing a photodiode in reverse bias or small forward causes the output current to be a linear function of input light intensity.
How is the dark current of a photodiode determined?
It must be noted that when a reverse bias is applied some current will flow without illumination. The “dark current” is specified for every device. In cases where a very low bias voltage is used, shunt resistance is specified. This is determined by measuring dark current with +/-0.010 volts applied bias.
When to apply breakdown voltage to a photodiode?
Breakdown Voltage is the largest reverse voltage that can be applied to the photodiode before there is an exponential increase in leakage current or dark current. Photodiodes should be operated below this maximum applied reverse bias or damage to the photodiode may occur. Breakdown voltage decreases with an increase in temperature.
Which is the largest reverse voltage for a photodiode?
Breakdown Voltage is the largest reverse voltage that can be applied to the photodiode before there is an exponential increase in leakage current or dark current. Photodiodes should be operated below this maximum applied reverse bias or damage to the photodiode may occur.
Can a photodiode be reverse biased or forward biased?
The photodiode can be forward biased, but current generated will flow in the opposite direction. This is why most photodiodes are reversed biased or not biased at all. Some photodiodes cannot be forward biased without