How to distinguish between Schottky, Fast recovery and Ultra Fast recovery Diodes

How to distinguish between Schottky, Fast recovery and Ultra Fast recovery Diodes.
Fast recovery diodes (FBR), ultra fast recovery diodes (SRD) and Schottky diodes (SBD) are widely used in high frequency, high current rectifier and continuous current circuits.
Schottky diodes use Schottky to block the reverse voltage on the metal or semiconductor contact surface, allowing the current to conduct in one direction. Different from the traditional diodes, the structures of Schottky and PN junctions are very different. Fast recovery diode, as its name implies, is a semiconductor diode that can quickly recover reverse time.
Schottky diodes are diodes based on the potential barrier formed by the contact between metal and semiconductors, referred to as Schottky Barrier Diode diodes. Schottky diodes have the advantages of forward voltage reduction (0.4 Murray 0.5V), short reverse recovery time (10-40 nanoseconds), large reverse leakage current, low voltage resistance, generally lower than 150V, and are mostly used in low voltage applications.
Fast recovery diodes refer to diodes with short reverse recovery time (below 5us). Gold-doped measures are often used in technology, PN junction structure is adopted in structure, and some improved PIN structure is adopted. Its forward voltage drop is higher than that of ordinary diodes (1-2V), and the reverse voltage is less than 1200V. In terms of performance, it can be divided into two levels: fast recovery and ultra-fast recovery. The reverse recovery time of the former is hundreds of nanoseconds or more, while that of the latter is less than 100 nanoseconds.
Ultrafast recovery diode (fred) is a kind of semiconductor diode with good switching characteristics and ultra-short reverse recovery time, which is often used as continuous current, absorption, clamping, isolation, output and input rectifier for switching devices in high frequency inverter devices, so that the functions of switching devices can be brought into full play. Ultra-fast recovery diode is an indispensable important device for the development of high-frequency electrical equipment (above 20khz) and high-frequency equipment solid state.