Inorganic 2D Luminescent Materials: Structure, Luminescence Modulation, and Applications

Abstract

Inorganic luminescent semiconductors have triggered burgeoning research interest in all‐solid‐state light‐emitting devices over the past decades owing to their band‐to‐band transitions along with their high efficiency and excellent long‐term stability compared with most organic luminescent materials. Recent booming developments in 2D materials demonstrate their fascinating tunable layer‐dependent electronic structures, strong light–matter interactions, high carrier mobilities, and broad spectral ranges at the 2D limit, which are promising for high‐performance light‐emitting devices. Here, state‐of‐the‐art 2D luminescent nanomaterials are reviewed from the fundamental aspects of crystal structures and electronic properties to practical applications, providing insights into the luminescence mechanism. Many research paradigms are comprehensively discussed to elaborate ingenious luminescence modulation strategies through control of the microstructure, such as the number of layers, defects, morphologies, charge carriers, heterostructures, and surface states of 2D systems. Promising applications of 2D luminescent systems in light‐emitting diodes, lasers, and bioimaging and biosensing devices are systematically illustrated. Finally, by summarizing the luminescence in 2D materials, challenges are proposed, which will provide new opportunities for developing 2D luminescence physics, luminescent materials, and related light‐emitting device applications.

2D Homojunctions for Electronics and Optoelectronics

“…Toward this end, considerable efforts have been devoted not only to investigate their fundamental properties but also to explore their practical applications. So far, a large variety of 2D electronic and optoelectronic prototype devices have been developed for field-effect transistors (FETs), [9][10][11][12] light-emitting diodes (LEDs), [13][14][15][16] and photodetectors. [17][18][19][20][21][22] For many of these devices, the realization of their functionalities is dominantly dependent on the junctions formed at the interface of two contacting semiconductors.…”

Development of fluorinated benzils and bisbenzils as room-temperature phosphorescent molecules

“…The development of organic light-emitting molecules is recognized as one of the most important studies because of the broad application of these compounds as fluorescence probes, bio-imaging materials, and biosensors in biomedical diagnostics [1][2][3][4] and as organic light-emitting diodes in the technological field [5][6][7][8]. Among the organic light-emitting molecules de- veloped thus far, extended π-conjugated compounds (e.g., pyrenes and perylenes) emit fluorescence, which is a radiative deactivation process from the lowest singlet (S 1 ) excited state to the ground (S 0 ) state [9].…”

Aggregation‐Induced Emission Luminogens Married to 2D Black Phosphorus Nanosheets for Highly Efficient Multimodal Theranostics

“…Among the various diagnostic imaging techniques, fluorescence imaging (FLI) has emerged as a powerful tool for noninvasive cancer diagnosis by virtue of its superb selectivity and sensitivity, relatively low cost, and excellent reproducibility. [ 9–11 ] Moreover, some fluorophores have been recognized to be significantly efficient as photosensitizers (PSs) for photodynamic therapy (PDT), which is an emerging therapeutic modality for cancer treatment, holding intrinsic advantages such as minimal invasiveness, insignificant side effects, high spatiotemporal precision, and excellent light‐controllable feature. [ 12–16 ] Considering their notable characteristics, the integration of FLI with PDT in a single formulation with precise spatial colocalization has been proven to be a prominent protocol for cancer theranostics.…”