Pin Diode Full Form

What is the full form of PIN Diode?

The full form of the pin diode is “Positive-Intrinsic-Negative diode”. A PIN diode is a semiconductor device that is made from a combination of p-type and n-type semiconductor material, in which the high resistivity intrinsic layer "I" is positioned between the two semiconductor material layers, such as P and N. A PIN diode is a diode with a sizable, undoped intrinsic semiconductor region sandwiched between a p-type semiconductor and an n-type semiconductor region. In 1950, Jun-Ichi Nishizawa and his associates created the PIN photodiode. Because they are employed for ohmic connections, the p- and n-type areas are frequently highly doped. In contrast to a typical p-n diode, the intrinsic area is wide. The broad intrinsic area makes the PIN diode a subpar rectifier (one usual function of a diode), but also makes it appropriate for attenuators, rapid switches, photodetectors, and high-voltage power electronics applications.

This Story also Contains

1. What is the full form of PIN Diode?
2. Characteristics of Pin Diode
3. Photovoltaic cell and photodetector

Characteristics of Pin Diode

• The common diode equation for low-frequency communications is followed by the PIN diode. The diode appears to be virtually a perfect resistance (extremely linear, even for strong signals) at higher frequencies. The P-I-N diode contains a sizable stored charge that is free floating in a substantially intrinsic region. The diode switches off when the stored charge is entirely swept at a low enough frequency.

• The diode never switches off at higher frequencies because there is not enough time to sweep the charge out of the drift region. The length of a PIN diode's reverse recovery time, which measures the amount of time needed to sweep the stored charge from the junction, is considerable. The reverse recovery time is predetermined for a given semiconductor material, on-state impedance, and minimum useable RF frequency.

• One type of P-I-N diode, the step recovery diode, makes use of this property to produce a narrow impulse waveform suitable for frequency multiplication with high multiples by taking advantage of the abrupt impedance change at the end of the reverse recovery.

• The depletion zone is almost entirely contained within the intrinsic region in a PIN diode. In comparison to PN diodes, this depletion region is substantially larger and nearly constant. This is true regardless of the reverse bias that is given to the diode. This expands the area where an incoming photon can produce electron-hole pairs. A PIN junction is used in the fabrication of some photodetector devices, such as PIN photodiodes and phototransistors (in which the base-collector junction is a PIN diode).

• There are certain trade-offs in the diode design. With no impact on the minimum amount of time needed to sweep the charge from the intrinsic region, increasing the intrinsic region's area increases the stored charge while decreasing the RF on-state resistance, increasing reverse bias capacitance, and increasing the drive current needed to remove the charge during a fixed switching time. The number of stored charges increases as the intrinsic region's thickness increases, while the minimum RF frequency and reverse-bias capacitance also decrease.

• However, the forward-bias RF resistance remains unchanged, and the minimum time needed to sweep the drift charge and change from low to high RF resistance increases. Commercially available diodes come in a range of shapes for application in various RF bands.

Photovoltaic cell and photodetector

• In fibre optic network cards and switches, PIN photodiodes are utilised. The PIN diode functions as a reverse-biassed photodetector. Normally, the diode does not conduct under reverse bias (save a small dark current or leakage).

• An electron-hole pair is produced when a photon with enough energy penetrates the depletion zone of the diode. Current is produced when the carriers are swept away from the area by the reverse-bias field.

• Avalanche multiplication is a technique some detectors can employ. The PIN structure, also known as the p-i-n junction, of a solar cell, uses the same technique. In this instance, a PIN structure's superior long-wavelength response makes it preferable to a traditional semiconductor p-n junction. Long-wavelength radiation causes photons to travel far into the cell.

• However, only electron-hole pairs produced in and close to the depletion area are able to contribute to the creation of current. Deep inside the device, across the intrinsic region, the depletion region of a PIN structure is present.

• The creation of electron-hole pairs is made possible by the greater depletion width, which raises the cell's quantum efficiency. PIN structures are typically used in amorphous silicon thin-film cells. The NIP structure, a variant of the PIN structure, is used in CdTe cells in contrast. In a NIP structure, an inherent CdTe layer is sandwiched between n-doped CdS and p-doped ZnTe; in contrast to a PIN diode, photons impinge on the n-doped layer.

• If a PIN photodiode is employed as a semiconductor detector, it can also detect ionising radiation. One of the most crucial factors in contemporary fibre-optic communications is the speed of optical transmitters and receivers.

• The photodiode's parasitic (unwanted) capacitance is decreased as a result of its modest surface area. Modern pin photodiodes have a bandwidth that can operate in the microwave and millimetre wave spectrum.