NOVELTY - Production of a perylene diimide crystalline compound comprises subjecting perylene diimide crystalline compound to physical vapor transport.    USE - The method is for producing perylene diimide crystalline compound of (I) used as n-type organic semiconducting compound in organic field-effect transistor in the form of a thin film transistor provided on a substrate useful for producing an electronic device, organic LED, inverter, and organic solar cell (claimed). It is useful for providing electrical devices, optical devices, optoelectronic devices (e.g. semiconductor devices for communications, electroabsorptive modulators, and lasers), and/or mechanical devices. (I) Is used in diodes, inverters, sensors, bipolar transistors, tunnel diodes, modulation doped superlattices, light-sensing devices, biological system imagers, biological and chemical detectors, thermal or temperature detectors, Josephine junctions, nanoscale light sources, photodetectors such as polarization-sensitive photodetectors, gates, AND, NAND, NOT, OR, TOR, and NOR gates, latches, flip-flops, registers, switches, clock circuitry, static or dynamic memory devices and arrays, state machines, gate arrays, and any other dynamic or sequential logic or other digital devices including programmable circuits.    ADVANTAGE - Perylene diimide crystalline compound of (I) has good transistor performance and good air-stability. Transistor channel made of (I) has greater mobility than a channel made of non-crystalline semiconductor.    DETAILED DESCRIPTION - Production of a perylene diimide crystalline compound of formula (I) comprises subjecting (I) to a physical vapor transport.    R1=(CnH2n)-R-a group or 3-5-membered saturated, optionally substituted carbocycle;    R-a, R-b=H or optionally substituted group from cycloalkyl, bicycloalkyl, cycloalkenyl, heterocycloalkyl, aryl, or hetaryl;    n=1-4;and    R2=(CnH2n)-R-b group or 3-5-membered saturated, optionally substituted carbocycle.    INDEPENDENT CLAIMS are included for:    (1) a method producing an organic field-effect transistor comprises providing a substrate comprising a gate structure, a source electrode, and a drain electrode located on the substrate; and applying (I) as n-type organic semiconducting compound to the area of the substrate where the gate structure, the source electrode, and the drain electrode are located;    (2) an organic field-effect transistor;    (3) a method of producing a substrate comprising a pattern of n-type organic field-effect transistors, where at least part of transistors comprise as n-type organic semiconducting compound, compound of (I);    (4) a substrate comprising a pattern of n-type organic field-effect transistors; and    (5) a method of producing an electronic device comprising providing on a substrate, a pattern of organic field-effect transistors.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of an inverter structure comprising N,N'-bis(2-phenylethyl)perylene-3,4:9,10-bis(dicarboximide) as n-type transistor and pentacene as p-type transistors.