Quantum dot infrared photodetectors: Advantages, challenges, and future research directions

Quantum dot infrared photodetectors (QDIPs) are positioned to become an important technology in the field of infrared (IR) detection, particularly for high-temperature, low-cost, high-yield detector arrays required for military applications. By addressing critical challenges inherent to epitaxial quantum dot (QD) material systems, the performance and applicability of QDIPs will continue to improve. In particular, three main approaches to combat epitaxial growth challenges and to obtain state-of-the-art performance in QDIPs are presented. First, epitaxial growth techniques designed to obtain uniform dopant incorporation in QD ensembles are reviewed. Second, bandgap engineering in QD heterostructures is presented as a tool to control device performance. Third, innovative photonic structures are discussed as a technique to increase and control absorption of incident IR radiation in QDIP heterostructures. Finally, preliminary investigations of a fundamentally different QD material system, namely colloidal QDs, are presented as a future direction of QDIP research.