Question

A silicon diode in an adapter rectifying circuit has a carrier density of 10⁻²¹ in p material and 10²² in n material. The temperature of the charger changes from 27°C to 42°C, find the change in barrier potential of the diode.

A) Positive change
B) Negative change
C) No change
D) Insufficient information to determine

Answer 1

The change in temperature from 27°C to 42°C causes thermal energy to increase for charge carriers in a silicon diode, leading to a negative change (decrease) in the barrier potential.

Step-by-step explanation:

When the temperature of a silicon diode in an adapter rectifying circuit changes, the barrier potential of the diode also changes due to the temperature dependence of the semiconductor's intrinsic properties. As the temperature increases from 27°C to 42°C, the thermal energy given to the charge carriers also increases. This can cause a slight decrease in the barrier potential since the added energy makes it easier for the charge carriers to overcome the potential barrier. Therefore, the barrier potential is expected to change in a negative direction (it gets smaller).