Interfacial engineering of carbon nanotube nano-emitters for high-efficiency photonics, quantum communication, and biomedical applications

Abstract

The near-infrared (NIR) emission and the excellent excitonic properties of carbon nanotubes (CNTs) are the basis for their potential use as nanoscale light sources in photonics, biomedical applications, and quantum communication. However, these are impeded by exciton quenching, environmental instability, and, in terms of chirality control, but only limited control. In this review, we summarize in depth the recent progress in interfacial engineering strategies to address these challenges, such as chemical defect functionalization, protective encapsulation, nanoscale heterostructure integration with two-dimensional (2D) and photonic materials, and chirality-selective self-assembly. It also reviews the photoluminescence (PL) and electroluminescence (EL) processes of CNT emitters, with a particular focus on the effect of interface interaction on exciton dynamics, emission efficiency, and device performance. Applications in silicon photonics, single photon sources for quantum optics, flexible optoelectronics, and NIR bio-imaging are critically discussed and key challenges, including dark exciton bottlenecks, interfacial degradation, scalable fabrication, and deterministic control of chirality, are discussed. The current review includes an overview of interfacial engineering, optical emission mechanisms, heterostructure design, and new surface engineering optimization strategies based on AI, unlike previous reviews that have concentrated on either CNT emitters or single interface modification strategies. It also pinpoints existing research gaps and outlines future directions for the development of high efficiency, stable and scalable CNT-based photonic and optoelectronic devices.