Comparison of Intersubband Quantum-Well and Interband Graphene-Layer Infrared Photodetectors

We compare the characteristics of the intersubband quantum-well infrared photodetectors (QWIPs) based on the traditional semiconductor materials and the interband graphene-layer infrared photodetectors (GLIPs) based on van der Waals heterostructures. We show that the responsivity and dark-current-limited detectivity of GLIPs exceed those of QWIPs. This is because of a stronger radiation interband absorption in the GLs, a smaller capture probability of electrons into the GLs, and a higher activation energy of the electron thermionic and tunneling escape from the GLs in comparison with those in the QWs.