(US4812352-A)      An article has on at least 1 major surface of a substrate support a microlayer of an array of discreet, uniformly oriented, crystalline, solid microstructures made of an organic cpd. consisting of planar molecules of chains or rings over which pi-electron density is extensively delocalised. The organic cpd. is pref. a polynuclear aromaic hydrocarbon or a heterocyclic aromatic cpd., esp. (metal free) phthalocyanine or a porphyrin. The length of the microstructures is in direct proportion to the thickness of the microlayer. The article can be flexible or rigid and can be shaped. The microstructures are whiskers having an aspect 10-80.    USE -   Used for light trapping, energy absorption, imaging, data transmission and storage and gradient index applications. (15pp)    (US5039561-A)      Article is prepd. which comprises a substrate, bearing on at least one of its major surfaces, a microlayer comprising an array of discrete, uniformly oriented, crystalline, solid microstructures (I). (I) comprises an organic cpd. (II) in which its mol. is planar and comprises chains or rings over which pi-electron density is extensively delocalized. Firtly, a substrate is provided. Secondly, cpd. (II) is vapour-deposited on the substrate. Finally, the substrate and the cpd. (II) deposited in the second step, are annealed at 165-230 deg. C for 0.5-6 hours, in a vacuum lower than about 1x10power-3 Torr, to form the microlayer.    USE -   Articles so obtd. are suitable for many forms of light trapping, energy absorption etc., depending on the configuration of the microstructures.    (15pp)    (JP2579950-B2)      Article comprises a substrate carrying a micro-layer of organic material comprising an array of discrete, uniformly oriented, crystalline, solid, organic microstructures. Pref. the organic cpd. is planar and comprises chains or rings over which pi-electron density is extensively delocalised.    Pref. cpds. are polynuclear (heterocyclic)aromatics, esp. perylenes, phthalocyanines and porphyrins.    USE/ADVANTAGE -   In a wide range of device for light trapping, energy absorption, imaging, data transmission and storage, and gradient applications. The microlayer has a high surface area and can be easily formed on a wide range of large-area substrates.