What is Forward bias?
Applying a positive voltage to the p side and a negative voltage to the n side. The barrier drops and current flows readily. The opposite is reverse bias, under which almost no current flows.
Field: PN junctions and diodes
Forward bias in the explanations
In a pn junction at equilibrium the two exactly cancel so the net current is zero; under forward bias diffusion wins and current flows.
What causes a diffusion current to flow in a semiconductor?This is forward bias, and current grows exponentially with voltage.
How is voltage applied to forward-bias a PN junction diode?Under forward bias, conductivity modulation lowers the i-layer resistance, and under reverse bias it is highly resistive, so PIN diodes also serve as RF switches and variable attenuators.
Which is a characteristic of a PIN diode, which has a light…
Questions that mention Forward bias (5)
- What causes a diffusion current to flow in a semiconductor?
- How is voltage applied to forward-bias a PN junction diode?
- Which is a characteristic of a PIN diode, which has a lightly doped i-layer between the p and n layers?
- In a forward-biased PN junction, which capacitance arises from the storage of injected minority carriers?
- What is the state of the junctions when a bipolar transistor is in the saturation region?
Related terms
Built-in potential Conductivity modulation Diffusion capacitance Junction capacitance (depletion capacitance) Saturation region Current gain (hFE) Avalanche breakdown Depletion layer Ideality factor Ohmic contact