Bandlückenprofil

Bandlückenprofil refers to the graphical representation of the energy gap in a semiconductor material as a function of position. In an ideal, homogeneous semiconductor, the band gap is constant throughout the material. However, in real-world devices, variations in composition, doping concentration, strain, or temperature can lead to spatial variations in the band gap. The bandlückenprofil visualizes these variations, typically showing the energy of the conduction band edge and valence band edge as a function of one spatial dimension.

Understanding the bandlückenprofil is crucial for designing and analyzing semiconductor devices such as transistors, solar cells, and LEDs. For instance, in a transistor, a carefully engineered bandlückenprofil can create potential barriers that control the flow of charge carriers. In solar cells, a graded band gap can help to efficiently separate and collect photogenerated electrons and holes, thereby improving device performance. Similarly, in LEDs, specific bandlückenprofile can influence the emitted light's wavelength and efficiency.

Techniques like photoluminescence (PL) spectroscopy and cathodoluminescence (CL) spectroscopy can be used to probe the bandlückenprofil. By analyzing the emitted light's spectrum and its spatial distribution, researchers can infer the local band gap energies and map out the bandlückenprofil across a sample. Transmission electron microscopy (TEM) can also provide direct imaging of structural features that influence the band gap. The study of bandlückenprofile is a fundamental aspect of semiconductor physics and device engineering.