Zero Reverse Recovery in SiC Schottky Diodes: What It Means for Switching Loss and Efficiency

The behavior comes from the device structure. 

A silicon diode (PN diode) uses both majority and minority carriers. During conduction, minority carriers are injected into the junction. When the diode switches, this stored charge must be removed before the device can block voltage. 

A Schottky diode uses a metal–semiconductor junction. Conduction occurs through majority carriers only, so there is no significant stored minority charge that needs to be removed during switching.

As a result:

• reverse recovery charge (Qrr) is negligible
• reverse recovery current is minimal
• switching behavior is fast

This is why SiC Schottky diodes are well suited for high-frequency power converters. 

Reverse Recovery in Silicon PN Diodes

Reverse recovery in a PN diode is tied to stored charge in the junction.

When the current changes direction:

• Stored charge remains for a short time
• Current flows in reverse while the charge is removed
• The diode then starts blocking voltage

This produces a reverse current spike and additional switching loss.

Reverse Recovery Behavior

Stage	Description
Storage time	Charge remains in the junction after current crosses zero
Reverse current	Current flows in reverse while charge is removed
Recovery completion	The diode begins to block reverse voltage

This reverse current is handled by the switching device in the circuit.

 

Comparison of Silicon and SiC Diodes

The difference in switching behavior comes from how charge is handled inside the device.

Silicon vs SiC Diodes

Parameter	Silicon Fast Recovery Diode	SiC Schottky Diode
Conduction mechanism	Majority and minority carriers	Majority carriers only
Reverse recovery charge (Qrr)	High	Near zero
Switching speed	Moderate	Fast
Switching losses	Higher	Lower
EMI generation	Higher	Lower
High-frequency performance	Limited	Better

The gap becomes more noticeable as switching frequency increases.

Impact of Reverse Recovery on Switching Losses

When reverse recovery occurs, the reverse current flows through the switching device as it turns on. This increases switching loss and adds heat.

A simple way to estimate this loss is:

Prr ≈ Qrr × V × fs

Where:

Parameter	Description
Qrr	Reverse recovery charge
V	Reverse voltage
fs	Switching frequency

With SiC Schottky diodes, Qrr is very low, so this part of the switching loss is reduced.

Capacitive Effects in SiC Schottky Diodes

Even though reverse recovery charge is negligible, switching behavior is still influenced by the diode’s junction capacitance.

During switching, this capacitance must be charged and discharged. This creates a current component that contributes to switching loss, especially at higher voltages and switching frequencies.

As a result:

• switching losses associated with reverse recovery are significantly reduced 
• but not eliminated
• junction capacitance becomes the dominant switching loss mechanism once Qrr is negligible 

 In high-frequency converter design, both reverse recovery charge (Qrr) and junction capacitance should be considered.

Benefits in High-Frequency Power Converters

Many SiC Schottky diodes also have low forward voltage, which helps reduce conduction losses.

• Lower reverse recovery charge improves switching behavior in several ways: 

• lower switching losses 
  

• better efficiency 
  

• less EMI 
  

• higher switching frequency 
  

• lower stress on the switching device
  

Many SiC Schottky diodes are optimized for forward voltage performance, helping reduce conduction losses. 

For high-voltage efficiency optimization, see Gen4 Schottky Diodes for High-Voltage Efficiency

Applications That Benefit from SiC Schottky Diodes

These diodes are used where switching losses matter.

Typical Applications

Application	Role of the Diode
PFC circuits	Boost diode in AC-DC stage
Data center and telecom power	High-efficiency switching
EV charging systems	AC-DC conversion
Solar inverters	Fast switching in DC-AC stage
Industrial SMPS	Reduced switching loss

As switching frequencies increase, these advantages become more important.

For automotive and high-voltage system design, see 1200V Gen4 SiC Schottky Diodes for Automotive Power Systems

Voltage Ratings for SiC Schottky Diodes

SiC Schottky diodes are typically used in higher voltage systems.

Typical Voltage Classes

Voltage Rating	Typical Applications
650 V	PFC and power supplies
1200 V	Solar, EV charging, industrial systems

 

Package Options for SiC Power Devices

Package selection affects thermal performance and layout.

 

For 650 V designs in surface-mount packages see Gen5 650V SiC Schottky Diode Series in D2-PAK Packages

The choice depends on power level and board design.

For higher power rectification beyond these package options, including TO-247 designs,, see 1200V Gen6 SiC Schottky Diode in TO-247AD Packages

SiC Schottky Technology in MCC’s Portfolio

MCC’s SiC portfolio includes different Schottky-based device structures and generations. In the current portfolio, Gen4 devices are positioned as JBS (Junction Barrier Schottky) technology.

This approach helps balance switching performance, leakage current, and thermal behavior.

Improvements across generations typically focus on:

• forward voltage
• leakage current
• thermal performance
• switching behavior

 

MCC Gen4 SiC Schottky Diodes

MCC offers a broad portfolio of SiC Schottky barrier rectifiers for high-efficiency power conversion.

The devices referenced here are part of the latest Gen4 SiC Schottky barrier rectifier release, covering 650 V and 1200 V voltage classes and designed for low switching losses and reliable operation in high-frequency converters.

Explore the latest release: 650 V-1200 V Gen4 Schottky Barrier Rectifiers

These devices are designed for:

• low switching losses
• low forward voltage
• reliable operation in high-frequency converters

Explore the latest NPI releases:

• 650 V Gen4 SiC Schottky Barrier Rectifiers 
• 1200 V Gen4 SiC Schottky Barrier Rectifiers 

These devices are available in DPAK, D2-PAK, and TO-220AC packages.

MCC’s broader SiC portfolio includes additional voltage classes, package options, and device configurations to support a wide range of power conversion designs.

Learn More About Selecting SiC Schottky Diodes

Reverse recovery is one factor when selecting a diode. Voltage rating, current capability, thermal performance, and package selection also need to be considered.

For a broader framework on device selection see Choosing The Right SiC Schottky