- #1
robina sr.
- 2
- 0
What are the characteristics of hetrojunction bipolar transistor , and how it is fabricated ... please any links any information will be helpful thanks 
Heterojunction is a junction between two different materials, typically semiconductors, with different bandgap energies. This results in unique electronic properties and allows for the creation of new devices with enhanced performance.
The fabrication process for heterojunction involves depositing the different materials onto a substrate using techniques such as chemical vapor deposition, sputtering, or molecular beam epitaxy. The layers are then patterned and etched to create the desired heterojunction structure.
Heterojunction devices have several main characteristics, including low leakage current, high carrier mobility, and improved efficiency due to the formation of a built-in electric field. They also have a wider range of bandgap energies, making them suitable for a variety of applications.
Heterojunction devices have a wide range of applications in electronics and optoelectronics, including solar cells, LEDs, transistors, and photodetectors. They are also used in high-speed and high-frequency devices, such as heterojunction bipolar transistors and high-electron-mobility transistors.
There are several techniques used for the characterization of heterojunctions, including electrical measurements, such as current-voltage and capacitance-voltage measurements, as well as optical measurements, such as photoluminescence and electroluminescence. Other techniques include scanning electron microscopy, atomic force microscopy, and X-ray diffraction.