Introduction:
Silicon diodes are widely used in rectifier circuits to convert alternating current (AC) to direct current (DC). However, they are not well-suited for low voltage rectifier operation. This is primarily due to their high breakdown voltage.

Explanation:
1. Breakdown voltage:
The breakdown voltage of a diode is the voltage at which it starts to conduct in the reverse bias direction. In other words, it is the voltage at which the diode "breaks down" and allows current to flow in the opposite direction. Silicon diodes typically have a high breakdown voltage, which means that they require a relatively high reverse voltage to start conducting. This is not desirable for low voltage rectifier operation, where the reverse voltage is usually small.

2. Cut-in voltage:
The cut-in voltage of a diode is the forward voltage required to make the diode start conducting in the forward bias direction. Silicon diodes have a relatively high cut-in voltage compared to other types of diodes, such as germanium diodes. This means that a higher forward voltage is needed to achieve conduction in a silicon diode. For low voltage rectifier operation, where the forward voltage is typically small, a low cut-in voltage is preferred.

3. Reverse saturation current:
The reverse saturation current of a diode is the current that flows through the diode when it is reverse biased and in the "off" state. Silicon diodes generally have a low reverse saturation current, which is beneficial for low power applications. However, it is not directly related to the suitability of silicon diodes for low voltage rectifier operation.

4. High temperature capability:
Silicon diodes are known for their high temperature capability. They can withstand higher temperatures compared to other types of diodes. While this characteristic is advantageous in certain applications, it is not directly related to the suitability of silicon diodes for low voltage rectifier operation.

Conclusion:
In conclusion, the main reason why silicon diodes are less suited for low voltage rectifier operation is their high breakdown voltage. The high cut-in voltage is also a factor, but it is not as critical as the breakdown voltage. The low reverse saturation current and high temperature capability of silicon diodes are not significant factors in this context.