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Nanocrystal/fullerene derivative inorganic-organic hybrid photodetectors exhibiting high detectivity for near-IR wavelengths and a linear power dependence are produced. The ultrafast electron transfer from the PbS crystals to the fullerene opens a new route to obtaining efficient photodetectors that are appealing, cost-effective alternatives to the currently available technology.

Organic semiconductorshave longbeen investigated for their potential of enhancing laser technology owing to their large conversion efficiency, gain cross-section, and bandwidth. Oligophenylene-based p-conjugated materials, having high carrier mobilities (up to 14 cm V 1 s ) and emission yields (ca. 30%), represent an important class of organic semiconductors for which amplified spontaneous emission (ASE) and low-threshold lasing action have been achieved in single crystals and ordered thin films. The last decade has also witnessed great advances in the growth of ordered oligophenylenes thin films with enhanced optoelectronic properties, for example, through surface dipole-assisted heteroepitaxy. The resulting needle-shaped aggregates, usually referred to as nanofibers, feature charge-carrier mobilities that range from ca. 10 2 to ca. 10 cm V 1 s , depending on fabrication technique, self-guiding of optical emission for light amplification, and lasing under femtosecond excitation. In particular para-sexiphenyl (p-6P) nanofibers have been highlighted as prototypical material system for self-assembled organic lasers, with large stimulated-emission cross-section

The great progress in the growth of ordered thin films of small linear molecules achieved in the past decade has made control of supramolecular arrangement and its effect on the physical properties frontline challenges for materials science. During film growth, multiple nucleation results in small, randomly oriented crystal domains. It has been recently shown that dipole-assisted, heteroepitaxial techniques allow deposition of thin films with unusual long-range order, consisting of crystalline aggregates that self-assemble to form nanofibers with sub-micrometer cross section, lengths of up to millimeters, orientational alignment extending to the centimeter size range, and controllable interaggregate distance. [1–3] These nanofibers have shown remarkable optical functionalities: photo- and electroluminescence, [2,4] optical waveguiding, [5,6] frequency doubling, [7] and optical gain. [8,9] Very recently, we have also shown that, depending on the growth condition, a single nanofiber behaves as a low-threshold self-assembled laser resonator, with randomly distributed optical feedback provided by 100 nm wide fiber breaks. [10] The high sensitivity of

Thumbnail image of graphical abstract Dyes inserted into the parallel nanochannels of a fully organic crystal show efficient light conversion over a wide visible spectral region, with 100 % conversion from UV to blue light. The Figure shows crystals containing either two (bottom) or three (top) dyes under UV illumination, and a top view of the structure of the dyes inserted into nanochannels (right)