Quantum entanglement, the most remarkable feature of quantum physics, is recognized as a resource for quantum information processing. The quest for quantum-computing devices has also produced great interest in entanglementformation in solid-state systems involving quantum effects. Indeed,the functionality of an increasing number of nanodevices is influenced by quantum correlations. In this work a theoretical approach developed in recent years to study the entanglement of fermions interacting via a Coulomb potential is presented, together with a number of applications to specific situations of physical interest in the field of charge transport in semiconductor nanostructures.