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#threshold voltage

3 public questions tagged with this topic.

Semiconductors, Types and Energy Bands

A germanium diode has a threshold voltage of approximately:

**Semiconductor properties** distinguish from conductors and insulators by temperature dependence and doping response. At 0 K intrinsic acts as insulator, conductivity due to thermally generated electron-hole pairs, number of outer electrons 4 for Si/Ge forming covalent bonds, each atom shares electrons, crystal with N atoms has 4N valence electrons, 2N bonds. The threshold voltage for a germanium diode, where forward current increases significantly, is approximately 0.2 V, lower than silicon due to its smaller energy gap. Substituting values gives 0.2 V, which matches expected behaviour for t

Ref: NCERT > Physics Book > Electronic Devices > Semiconductors, Types and Energy Bands

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p-n Junction, Depletion Region and Diode Characteristics

A silicon diode has a threshold voltage of approximately:

**p-n junction formation** diffusion of holes from p to n and electrons from n to p leaves ionized donors positive on n-side and acceptors negative on p-side, forming space-charge depletion region with electric field directed from n to p (positive to negative), barrier potential V_b ≈0.3 V Ge, 0.7 V Si, opposes further diffusion, drift current due to minority carriers swept by field balances diffusion at equilibrium net current zero. The threshold or cut-in voltage for a silicon diode is about 0.7 V, beyond which the forward current increases significantly. Substituting values gives 0.7 V, whi

Ref: NCERT > Physics Book > Electronic Devices > p-n Junction, Depletion Region and Diode Characteristics

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p-n Junction, Depletion Region and Diode Characteristics

The forward current in a p-n junction diode increases significantly beyond:

**p-n junction formation** diffusion of holes from p to n and electrons from n to p leaves ionized donors positive on n-side and acceptors negative on p-side, forming space-charge depletion region with electric field directed from n to p (positive to negative), barrier potential V_b ≈0.3 V Ge, 0.7 V Si, opposes further diffusion, drift current due to minority carriers swept by field balances diffusion at equilibrium net current zero. The forward current rises exponentially after the applied voltage exceeds the threshold (cut-in) voltage, reducing the barrier height significantly. Substituting

Ref: NCERT > Physics Book > Electronic Devices > p-n Junction, Depletion Region and Diode Characteristics

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