heterojunctions

A heterojunction is a boundary formed where two different types of semiconductor materials meet. These materials have distinct electrical properties, such as different energy gaps or electron affinities. When combined, they create a junction that can control the flow of electric current more effectively than uniform materials. This is essential in electronic devices like transistors and solar cells, as it allows engineers to tailor electrical behavior, improve efficiency, and enable new functionalities. Think of it as a carefully designed "interface" that leverages the unique properties of each material to enhance device performance.