Overview:
A power diode is a two-terminal semiconductor device that allows electric current to flow in one direction while blocking it in the opposite direction. An ideal power diode should possess certain characteristics to ensure efficient and reliable operation. Among these characteristics, a large reverse breakdown voltage is crucial for the diode's performance.

Explanation:
1. Role of Reverse Breakdown Voltage:
The reverse breakdown voltage is the maximum voltage that a diode can withstand in the reverse biased condition without undergoing breakdown. It is an essential characteristic for power diodes because it determines the diode's ability to block reverse voltage. Here's why a large reverse breakdown voltage is necessary:

- Protection against Voltage Spikes: Power diodes are commonly used in circuits to protect sensitive components against voltage spikes. These spikes occur when there is a sudden increase in voltage, which can damage or destroy electronic devices. By having a large reverse breakdown voltage, the power diode can effectively block these voltage spikes and protect the circuit.

- Prevention of Reverse Current: In a power diode, the reverse biased condition prevents the flow of current in the opposite direction. A large reverse breakdown voltage ensures that the diode can withstand high reverse voltages and effectively block any reverse current from flowing.

- Reliability and Durability: Power diodes are often subjected to harsh operating conditions, such as high temperatures and voltage fluctuations. A diode with a high reverse breakdown voltage can handle these conditions without breakdown, ensuring the device's reliability and durability.

2. Significance of Other Options:
Now, let's consider the other options provided and understand why they are not the ideal characteristics for a power diode:

- Low forward current carrying capacity: A power diode should have a high forward current carrying capacity to handle the flow of current in the forward direction. A low forward current carrying capacity would limit the diode's ability to handle high power applications.

- High ohmic junction resistance: The ohmic junction resistance should ideally be low in a power diode to minimize power losses. High resistance would result in increased power dissipation and decreased efficiency.

- High reverse recovery time: The reverse recovery time refers to the time taken by the diode to switch from the forward biased condition to the reverse biased condition. A high reverse recovery time would introduce delays and inefficiencies in circuit operation.

Conclusion:
In conclusion, a power diode with a large reverse breakdown voltage is considered ideal because it ensures protection against voltage spikes, prevents reverse current, and enhances the diode's reliability and durability. The other options provided in the question, such as low forward current carrying capacity, high ohmic junction resistance, and high reverse recovery time, are not desired characteristics for an ideal power diode.