PN Junctions and Energy Band Diagrams

<p>Vbi = Vt ln(Na * Nd / ni^2) (B)</p> Signup and view all the answers

<p>1.5 x 10^10 cm^-3 (A)</p> Signup and view all the answers

<p>2.4 x 10^13 cm^-3 (B)</p> Signup and view all the answers

<p>1.8 x 10^6 cm^-3 (A)</p> Signup and view all the answers

<p>4.26 x 10^-7 m (C)</p> Signup and view all the answers

<p>3.29 x 10^4 V/cm (B)</p> Signup and view all the answers

<p>0.6767 V (C)</p> Signup and view all the answers

<p>Increase (B)</p> Signup and view all the answers

<p>cm (D)</p> Signup and view all the answers

<p>Increasing $V_R$ increases $E_{max}$ (A)</p> Signup and view all the answers

<p>A PN junction (A)</p> Signup and view all the answers

<p>Metallurgical junction (A)</p> Signup and view all the answers

<p>They are uniform within each region (D)</p> Signup and view all the answers

<p>Valence band energy level (Ev) (B)</p> Signup and view all the answers

<p>Field-effect transistor (D)</p> Signup and view all the answers

<p>Built-in potential (B)</p> Signup and view all the answers

<p>$Wdep = \frac{2\epsilon_s (\phi_{bi} + | V_r |)}{qN_d}$ (D)</p> Signup and view all the answers

<p>0.12 μm (A)</p> Signup and view all the answers

<p>It widens the depletion layer (B)</p> Signup and view all the answers

<p>Distance related to the equilibrium carrier distribution (B)</p> Signup and view all the answers

<p>$W = \sqrt{\frac{2 \epsilon_s (V_{bi} + V_R)}{e(\frac{N_a + N_d}{N_a N_d})}}$ (D)</p> Signup and view all the answers

<p>0.9452 µm (A)</p> Signup and view all the answers

<p>2.738 µm (B)</p> Signup and view all the answers

<p>$1.43 \times 10^4$ V/cm (A)</p> Signup and view all the answers

<p>Vbi and W (C)</p> Signup and view all the answers

<p>$5 \times 10^{16}$ cm⁻³ (C)</p> Signup and view all the answers

<p>It increases. (A)</p> Signup and view all the answers

<p>Positively charged donors are left behind. (A)</p> Signup and view all the answers

<p>The difference between intrinsic Fermi levels in the p and n regions. (C)</p> Signup and view all the answers

<p>$Vbi = \phi Fn + \phi Fp$ (D)</p> Signup and view all the answers

<p>An electric field. (D)</p> Signup and view all the answers

<p>Majority and minority carriers in both p and n regions. (A)</p> Signup and view all the answers

<p>A region without charge carriers. (A)</p> Signup and view all the answers

<p>Majority carrier concentration. (D)</p> Signup and view all the answers

<p>To simplify the exponential relationship. (A)</p> Signup and view all the answers

<p>The depletion width increases. (C)</p> Signup and view all the answers

<p>They bend due to the electric field. (A)</p> Signup and view all the answers

<p>They represent energy barriers for electrons and holes. (A)</p> Signup and view all the answers

<p>Only in the depletion layer. (D)</p> Signup and view all the answers

<p>It is inversely proportional to it. (A)</p> Signup and view all the answers

<p>Equilibrium and charge imbalance. (A)</p> Signup and view all the answers

A semiconductor structure formed by joining P-type and N-type materials.

A device, such as a diode, that allows current to flow in one direction.

The interface where P-type and N-type regions meet in a PN junction.

An idealized PN junction with abrupt doping concentration changes.

A graphical representation showing energy levels in semiconductors at equilibrium.

The voltage developed across a PN junction in equilibrium, calculated as φbi ≈ 1V.

The width of the depletion region at a PN junction, often given by Wdep ≈ 0.12 μm.

Approximation of the depletion width, xN ≈ Wdep, calculated at 0.12 μm.

xP is determined by xN and doping concentrations, given by xP = 1.2 Å.

Increasing reverse bias widens the depletion layer at a PN junction.

The diffusion length of electrons in a pn junction.

The diffusion length of holes in a pn junction.

The maximum electric field in a pn junction.

Built-in voltage at zero bias in a pn junction.

The concentration of acceptor impurities in a p-type semiconductor.

The concentration of donor impurities in an n-type semiconductor.

The width of the depletion region in a pn junction.

Temperature at which the pn junction is analyzed, typically in Kelvin.

Width (W) of the depletion region at zero bias voltage.

W = √((2 * ε_s * (V_bi + V_R) * (N_a + N_d)) / (e * (N_a * N_d)))

Width (W) of the depletion region at 5 volts bias voltage.

E_max = (2 * (V_bi + V_R)) / W

Maximum electric field (E_max) at zero bias voltage.

Maximum electric field (E_max) at 5 volts bias voltage.

Physical constant measuring a material's ability to permit electric field lines.

Impurity levels of Na and Nd affecting junction characteristics.

The potential difference that balances the charge in a pn junction.

The amount of donor (Nd) and acceptor (Na) atoms in a semiconductor.

For part a, Nd=10^14 cm-3, Na=10^17 cm-3.

Vbi for Si with Nd=10^14 cm-3, Na=10^17 cm-3 is 0.635V.

Vbi for Ge with Nd=10^14 cm-3, Na=10^17 cm-3 is 0.253V.

For part b, Nd=5x10^16 cm-3, Na=5x10^16 cm-3.

Vbi for GaAs with Nd=5x10^16 cm-3, Na=5x10^16 cm-3 is 1.25V.

A junction with drastic change in doping concentration at zero bias.

The area in a semiconductor where charge carriers are depleted, affecting electric field formation.

Type of charge carrier that is present in greater concentration in a semiconductor region (electrons in n-region, holes in p-region).

Type of charge carrier that is present in lesser concentration in a semiconductor region (holes in n-region, electrons in p-region).

The energy level at which the probability of finding an electron is 50% at absolute zero temperature.

Number of electrons per unit volume per given energy state in the n-region of a semiconductor.

Number of holes per unit volume per given energy state in the p-region of a semiconductor.

The potential energy difference related to electron concentration in the n-region of a semiconductor.

The potential energy difference related to hole concentration in the p-region of a semiconductor.

The region in a semiconductor where charge carriers are absent, leading to a lack of free charge.

A semiconductor doped with elements that provide extra electrons, creating more negative charge carriers.

A semiconductor doped with elements that create holes, resulting in more positive charge carriers.

The state where diffusion of charge carriers balances out, creating stable electric fields.

The bending of the conduction and valence bands across the space charge region indicates a difference in voltage levels.