Carbazole derivatives are widely used in the development of organic semiconductors and optoelectronic devices. They play a key role in organic light-emitting diodes (OLEDs), where they serve as host materials or hole-transport layers due to their good thermal stability and efficient charge transport properties. Carbazole-based compounds are also important in photorefractive materials, solar cells, and fluorescent dyes.

In pharmaceuticals, carbazole scaffolds are found in bioactive molecules and natural products with antimicrobial, anti-inflammatory, and anticancer activities. Some synthetic derivatives are being studied for use in treating neurodegenerative diseases and cancer.

Additionally, carbazole is used in the production of dyes, pigments, and photoconductors for use in photocopiers and laser printers. Its ability to form stable radical species makes it valuable in materials requiring high durability and performance under light or electrical stress.