Semiconductor Physics Quiz

The ability of a material to conduct electric current. It is the reciprocal of resistivity.

The resistance of a material to the flow of electric current. It is the reciprocal of conductivity.

The ratio of the drift velocity of charge carriers to the applied electric field. It measures how easily charge carriers move in a material.

The velocity of charged particles in a material due to the influence of an electric field.

The resistance of a material to the flow of current per unit length and cross-sectional area.

The ability of a material to conduct electric current per unit length and cross-sectional area.

The speed at which charge carriers move in a material under the influence of an electric field.

The ratio of the drift velocity of charge carriers to the applied electric field. It measures how easily charge carriers move in a material.

In an extrinsic semiconductor, when the temperature increases, the intrinsic carrier concentration (which is a measure of free electrons and holes) doubles.

At room temperature, the current in an intrinsic semiconductor is due to both electrons and holes. These are the majority carriers.

Mobility (µ) represents how easily charge carriers move through a material in response to an electric field. It's measured as the drift velocity (v0) divided by the electric field strength (E0).

In a p-type semiconductor, the conductivity (σp) due to holes is calculated as the product of the hole concentration (p0), the charge of a hole (e), and the hole mobility (µp).

Resistivity is the measure of a material's resistance to electrical current. For semiconductors, resistivity generally decreases as temperature increases. This is because more charge carriers become available at higher temperatures.

If a semiconductor is transparent to light with a wavelength greater than a specific value (λ), its band gap energy (Eg) is less than the energy corresponding to that wavelength.

Materials with a positive temperature coefficient of resistance increase their resistance as temperature increases. Semiconductors and insulators exhibit this behavior.

The relationship between the concentrations of electrons (n) and holes (p) in a semiconductor, which states that the product of these concentrations is constant and equal to the square of the intrinsic carrier concentration (ni).

The band gap energy (Eg) is the minimum energy required for an electron to transition from the valence band to the conduction band, which is responsible for electrical conductivity. It determines the material's optical and electrical properties.

The product of the electron concentration (n) and hole concentration (p) in a semiconductor is always equal to the square of the intrinsic carrier concentration (ni). This holds true even for doped semiconductors.

The Fermi level in an n-type semiconductor moves upwards with increasing temperature.

The Fermi level in an intrinsic semiconductor shifts upwards with increasing temperature. This is because the energy gap between the valence and conduction bands decreases with increasing temperature, leading to an increase in the number of free electrons and holes.

The potential barrier in a p-n diode arises due to the depletion of charge carriers (electrons and holes) near the junction, creating a region with a lack of free charge carriers. This depletion region acts as a barrier to the flow of current.

Forward bias reduces the width of the potential barrier in a p-n junction. This allows more majority carriers to cross the junction, increasing the current flow.

Applying forward bias to a p-n junction decreases the width of the depletion zone. This occurs because the applied voltage pushes the majority carriers (electrons and holes) towards the junction, reducing the region with a lack of charge carriers.

Reverse bias increases the width of the depletion zone in a p-n junction diode. This happens because the applied voltage pulls the majority carriers away from the junction, enlarging the region with a lack of charge carriers.

Applying reverse bias to a p-n junction increases the potential difference across the depletion zone. This is because the applied voltage pulls the majority carriers away from the junction, creating a stronger electric field across the depletion region.

A p-n junction diode, when connected in series with a battery and a resistance, allows current to flow in one direction (forward bias) but blocks it in the other direction (reverse bias).

When a forward bias is applied to a p-n junction diode, the energy level of electrons in the n-type material increases relative to the energy level of holes in the p-type material.

When a reverse bias is applied to a p-n junction diode, the energy level of electrons in the n-type material decreases relative to the energy level of holes in the p-type material.

The depletion layer in a p-n junction diode acts as a barrier to the flow of both majority and minority charge carriers.

The process of electron-hole recombination in a forward-biased GaAs diode emits infrared radiation.

The emitter of a transistor is heavily doped to produce a high concentration of majority charge carriers, which are then injected into the base.

The base of a transistor is lightly doped to control the flow of charge carriers from the emitter to the collector.

The collector of a transistor is designed to collect the majority charge carriers from the base.

When a n-p-n transistor is used as an amplifier, a small signal applied to the base controls a larger current flowing through the collector.

A region in a p-n junction where mobile charge carriers (electrons and holes) are depleted, leaving behind immobile ions.

The depletion layer in the p-type region of a p-n junction contains immobile positive ions.

The depletion layer in the n-type region of a p-n junction contains immobile negative ions.

Holes are created by the absence of electrons in the valence band of a semiconductor.

In an unbiased p-n junction, the potential difference across the depletion layer creates an internal electric field that prevents further diffusion of charge carriers.

Applying reverse bias to a p-n junction diode increases the width of the depletion layer, which decreases the minority carrier current.

Increasing temperature in an n-type semiconductor increases the number of minority charge carriers (holes).

Increasing temperature in a p-type semiconductor increases the number of minority charge carriers (electrons).

A property of materials that quantifies the density of charge carriers (electrons or holes) present in them.

The Hall coefficient is a material property that describes the relationship between the Hall voltage, magnetic field, current, and charge carrier density. It provides information about the type of charge carriers (electrons or holes) and their density.

The Hall coefficient is the proportionality constant between the Hall voltage and the product of the magnetic field, current, and the charge carrier density.

The generation of an electromotive force (e.m.f.) across an open-circuited p-n junction when light is incident on it.

A device that converts light energy directly into electrical energy.

A device that converts light energy directly into electrical energy. They are typically made from silicon, a semiconductor material.

A device that converts light energy directly into electrical energy.

The p-n junction is the key component in solar cells. It is formed by joining a p-type semiconductor with an n-type semiconductor. When light strikes the junction, it creates electron-hole pairs which are separated by the junction's electric field, creating a voltage.

The Hall effect is a phenomenon observed when a current-carrying conductor or semiconductor is placed in a magnetic field. An electric field is generated perpendicular to both the current and magnetic field directions. This electric field is known as the Hall voltage or Hall field.