What is the simple definition of photodiode?
A photodiode is a semiconductor p-n junction device that converts light into an electrical current. The current is generated when photons are absorbed in the photodiode. Photodiodes may contain optical filters, built-in lenses, and may have large or small surface areas.
What is the meaning of sensitivity of photo diode?
Definition: The sensitivity of a photodiode is the ratio of amount of current flow with unit light irradiance. The dark current can be minimized in order to enhance the sensitivity of the photodiode.
What are the advantages of photo diode?
Advantages of photodiode :
- The photodiode is linear.
- Low resistance.
- A very good spectral response.
- Better frequency response.
- Low dark current.
- Fastest photodetector.
- Long lifetime.
- Low noise.
What is responsivity and quantum efficiency of a photo diode?
It can be calculated according to. where h ν is the photon energy, η is the quantum efficiency, and e the elementary charge. For example, a silicon photodiode with 90% quantum efficiency at a wavelength of 800 nm, the responsivity would be ≈ 0.58 A/W.
What are the different types of photodiode?
There are four types of photodiodes and they are:
- PN photodiode: The first photodiode to be developed was PN photodiode.
- PIN photodiode: These days PIN photodiode finds wide applications.
- Avalanche photodiode: Avalanche process is used for providing extra performances.
What is the temperature dependence of a diode?
In other words, the forward voltage drops 1.63 mV for every degree Celsius (or approximately 0.91 mV per degree Fahrenheit) According to the datasheet, a typical 1N4148 has somewhere between a -1 to -2 mV/°C temperature dependence, which means my diode is within spec (hooray!).
How are the characteristics of a photodiode affected by temperature?
TEMPERATURE EFFECTS All photodiode characteristics are affected by changes in temperature. They include shunt resistance, dark current, breakdown voltage, responsivity and to a lesser extent other parameters such as junction capacitance.
What is the rise and fall time of a photodiode?
The rise time and fall time of a photodiode is defined as the time for the signal to rise or fall from 10% to 90% or 90% to 10% of the final value respectively. This parameter can be also expressed as frequency response, which is the frequency at which the photodiode output de- creases by 3dB.
What can a photodiode be used for in a circuit?
Photodiode offers high operational speed. It provides a linear response. It is a low-cost device. It is a temperature-dependent device. And shows poor temperature stability. When low illumination is provided, then amplification is necessary. Photodiodes majorly find its use in counters and switching circuits.