Performance enhancement of quantum dot infrared photodetectors (QDIPs) via nanoscale light-matter interaction engineering: a review

Abstract Quantum dots (QDs) are zero-dimensional (0D) semiconductor nanostructures that provide three-dimensional (3D) quantum confinement. This confinement leads to discrete energy levels with a delta-function-like density of states (DOS), enabling superior optoelectronic characteristics such as monochromatic light emission, a low linewidth enhancement factor (α), and high-gain, low-threshold lasing. Consequently, QDs have become cornerstone materials for next-generation optoelectronic devices, including infrared photodetectors (QDIPs), laser diodes, and electro-optic (EO) modulators. However, the performance of epitaxial QDs is often constrained by latticemismatch-induced strain, leading to inherent trade-offs between active layer thickness and absorption efficiency. Furthermore, the intrinsic low filling factor due to the small physical size of 0D dots relative to the total active area and stochastic variations in dot size during growth induce inhomogeneous spectral broadening, which can dilute the theoretical advantages of their discrete