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Highly sensitive photodetectors play significant roles in modern optoelectronic integrated circuits. Constructing p-n junctions has been proven to be a particularly powerful approach to realizing sensitive photodetection due to their efficient carrier separation. Recently, p-n-junction photodetectors based on organic-inorganic hybrid perovskites, which combine favorable optoelectronic performance with facile processability, hold great potential in practical applications. So far, these devices have generally been made of polycrystalline films, which exhibit poor carrier-transport efficiency, impeding the further improvement of their photoresponsivities. Here, a type of ultrasensitive photodetector based on single-crystalline perovskite p-n-junction nanowire arrays is demonstrated. The single-crystalline perovskite p-n-junction nanowire arrays not only possess high crystallinity that enables efficient carrier transport but also form a built-in electric field facilitating effective carrier separation. As a result, the devices show excellent photosensitivity over a wide spectral range from 405 to 635 nm with an outstanding responsivity of 2.65 × 10

Inorganic perovskite single crystals have emerged as promising vapor-phase processable structures for optoelectronic devices. However, because of material lattice mismatch and uncontrolled nucleation, vapor-phase methods have been restricted to random distribution of single crystals that are difficult to perform for integrated device arrays. Herein, an effective strategy to control the vapor-phase growth of high-quality cesium lead bromide perovskite (CsPbBr3 ) microplate arrays with uniform morphology as well as controlled location and size is reported. By introducing perovskite seeds on substrates, intractable lattice mismatches and random nucleation barriers are surpassed, and the epitaxial growth of perovskite crystals is accurately controlled. It is further demonstrated that CsPbBr3 microplate arrays can be monolithically integrated on substrates for the fabrication of high-performance lasers and photodetectors. This strategy provides a facile approach to fabricate high-quality CsPbBr3 microplates with controllable size and location, which offers new opportunities for the scalable production of integrated optoelectronic devices.

Organic color-graded optical waveguides permit low-power photonic analogies of diode/transistors based on the energy-transferred conversion of exciton species. The donor-acceptor junction can asymmetrically output blue/red colors due to the mono-directional energy transfer during light propagation. The switching function of transistors is achieved with an additional gate input by altering the ground state density of acceptors. These organic heterogeneous waveguides are further cascaded together to steer the guided light flows for potential applications in photonic integrations.

A novel approach to manipulating multiple optical signals at subwavelength scale is proposed in dendritic organic/metal nanowire heterostructures. The heterostructures are prepared by embedding Ag nanowires in fac-tris(2-phenylpyridine) iridium microwires during the self-assembly in liquid phase. Optical signals inputted from the organic waveguide can be selectively transferred to the predetermined subwavelength output ports based on the angular dependence of the photon-plasmon coupling.

Organic/organic single-crystal coaxial p-n heterojunction nanowire arrays consisting of p-type copper phthalocyanine (CuPc) and n-type 5,10,15,20-tetra(4-pyridyl)-porphyrin (H(2)TPyP) are fabricated through a one-step physical vapor transport (PVT) process. Each single junction wire revealed high photodependent rectifying and sensitive photoresponsive characteristics in devices of light-controlled diodes and photoswitches. The typical photovoltaic device based on a single p-n junction exhibited a high open-circuit voltage (Voc) of 0.64 V.

Organic photonic heterostructures are constructed through a template-free self-assembly method. The host-guest intermolecular interactions play an essential role in the formation of various block orange-blue-orange and blue/green microtubes. The spatial distribution of excitons is engineered to investigate the excitonic behaviors in light propagation along the axial heterostructures. These results offer a new route to the integration of organic photonic building blocks for optical processing applications.

The transparent bulk polymer nanocomposites blended with rare earth nanoparticles are prepared through the radical polymerization of trimethylolpropane trimethylacrylate (TMPTMA). These materials produce continuously tunable second harmonic (SH) radiation under illumination of a wide spectral range of fundamental waves (750-850 nm). The SHG efficiency can be controlled well by altering the Tb(3+) doping content in the nanoparticles.

This article presents a comprehensive review of recent progress of research dedicated to low-dimensional nanomaterials constructed from functional low-molecular-weight organic compounds, whose optoelectronic properties are fundamentally different from those of their inorganic counterparts. After introducing the development of inorganic and organic macromolecular nanomaterials, we begin with a general review of the construction strategies for achieving both zero-dimensional (OD) and one-dimensional (ID) nanostructures from small organic functional molecules. We then provide an overview of the unique optoelectronic properties induced by molecular aggregation in the nanostructures. Special emphasis is put on the luminescent properties that are different from those of the corresponding bulk materials, such as aggregation-induced enhanced emission, fluorescence narrowing, multi-color emission, and tunable and switchable emissions from doped nanostructures. We conclude with a summary and our personal view of the direction of future development of organic opto-functional nanomaterials and devices.