The Impact Mechanism of Interfacial Intermixing on the Dark Current of Interband Cascade Infrared Photodetectors

Antimonide superlattice interband cascade infrared photodetectors (ICIPs) are novel semiconductor devices that enable the directional transport of photogenerated carriers within multi-stage absorbers formed through phonon-assisted tunneling, allowing for higher operating temperatures. The dark current of infrared detectors has been the main factor limiting their performance. ICIPs have complex interfaces characterized by multi-layer heterostructures. Interfacial intermixing leads to band misalignment in the actual device structure, affecting both photocurrent transport and the dark current mechanism. Based on previous research on interfacial intermixing and the computational results from the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{k}\cdot \mathbf{p}$</tex> model, this paper explores the impact of interfacial intermixing on dark current and establishes a dark current model for ICIP at high operating temperatures. The calculation results are compared and analyzed against experimental results, partially validating its accuracy and providing a theoretical foundation for subsequent research.