What is a germanium diode, its basic structure, performance parameters, working principle, application examples, differences and development history between germanium and silicon diodes 1

Germanium diode is an AT93C66B-SSHM-T diode made of germanium (Ge) material. Germanium is a common semiconductor material with a lower bandgap (about 0.67 eV), which was used earlier than silicon (Si) to manufacture semiconductor devices. Below, we will provide a detailed introduction to the basic structure, performance parameters, working principle, application examples, differences from silicon diodes, and development history of germanium diodes.

1、 Basic structure:

The basic structure of a germanium diode consists of two regions, namely an N-type region and a P-type region. The germanium material in the N-type region is doped with impurities, making it the main source of electron carriers. The germanium material in the P-type region is doped with another impurity, making it the main source of hole carriers. The junction formed between two regions is called a PN junction. The formation of PN junction is achieved by doping an appropriate amount of impurities into germanium material.

2、 Performance parameters:

1. Forward Voltage: Germanium diodes can only conduct under forward voltage, and their conduction voltage is generally 0.2V-0.3V, which is lower than the typical conduction voltage of silicon diodes (about 0.6V).

2. Maximum Reverse Voltage: Germanium diodes should have a certain resistance to breakdown under reverse voltage, and their maximum reverse voltage is generally 30V-60V.

3. Maximum Forward Current: Germanium diodes should have a certain carrying capacity under forward current, and their maximum forward current is generally between 100mA-500mA.

4. Reverse Recovery Time: During the process of a germanium diode transitioning from conduction to cutoff, its PN junction requires a certain amount of time to recover, which is called the reverse recovery time.