Why heterojunction are used in heterostructure?

Heterojunctions are used in heterostructures to leverage the distinct electronic properties of different semiconductor materials, enabling improved performance in devices like transistors and solar cells. By combining materials with varying bandgaps, heterojunctions facilitate efficient charge separation and transport, enhancing device efficiency and speed. Additionally, they can enable tailored band alignment for specific applications, allowing for better control of electronic and optical properties. Overall, heterojunctions play a crucial role in advancing semiconductor technology and improving device functionality.