NOVELTY - A three-dimensional indium-tin-oxide electrode (3) comprises: conductive layer (31), and several ITO nanorods (32) formed on conductive layer; where indium-tin-oxide nanorods have adjustable length of 10-1500 nm, adjustable diameter of 10-120 nm, and adjustable distribution density on conductive layer of 1x 106 to 5x 1010 per cm2.    USE - As three-dimensional indium-tin-oxide (ITO) electrode, for use in organic solar cell; and for fabricating three-dimensional ITO electrode and organic solar cell (claimed). The three-dimensional ITO electrode is also useful in dye-sensitized solar cells and organic light emitting diodes (OLEDs).    ADVANTAGE - The three-dimensional ITO electrode and in turn the organic solar cell comprising the ITO electrode are capable of increasing contact area to active layer (or dye molecules), enhance carrier collection or injection, improve flowing efficiency and uniformity of electric current, boost device conversion efficiencies, protect active layer from being damaged by non-uniformity of electric current and hence can increase lifetime of applied organic optoelectronic devices i.e. organic solar cell. In addition, some drawbacks due to usage of tin material can be avoided because the ITO material used is advanced in high stability (high resistance to acid or base), low electric resistance, and high transmittance to visible light. These enable cost of fabricating organic optoelectronic devices with high efficiency to be lowered and simultaneously enable process time to be reduced. Further, method for forming three-dimensional ITO electrode utilizes oblique evaporation method to form several ITO nanorods on conductive layer of substrate, hence process time can be reduced, and cost of equipment and material can be lowered. Thus, the method is advanced in industrial application for large quantities to be manufactured.    DETAILED DESCRIPTION - A three-dimensional indium-tin-oxide (ITO) electrode (3) comprises: conductive layer (31), and several ITO nanorods (32) formed on conductive layer; where ITO nanorods have adjustable length of 10-1500 nm, adjustable diameter of 10-120 nm, and adjustable distribution density on conductive layer of 1x 106 to 5x 1010 per cm2. The ITO nanorods have adjustable length of 100-200 nm, adjustable diameter of 30-50 nm, and adjustable distribution density on conductive layer of 1x 108 to 1x 1010 per cm2. The conductive layer is transparent conductive layer, metal layer, conductive ceramics layer, semiconductive layer, or conductive polymer layer. INDEPENDENT CLAIMS are included for the following:    (1) fabricating three-dimensional ITO electrode involving: preparing evaporator having reacting chamber; evaporating source placed at bottom of reacting chamber, and substrate holder facing evaporating source and connecting to ceiling of reacting chamber; importing substrate having conductive layer into chamber and holding substrate by substrate holder, tuning angle between normal direction of substrate and bottom of chamber to 0-90 degrees ; and processing oblique evaporation to form several ITO nanorods on conductive layer of substrate, to obtain three-dimensional ITO electrode locating on substrate;    (2) evaporator for forming three-dimensional ITO electrode on conductive layer forming on substrate, comprising: reacting chamber; evaporating source placed at bottom of reacting chamber; and substrate holder facing evaporating source and connecting to ceiling of reacting chamber, such that when substrate having conductive layer forming is held by substrate holder, angle between normal direction of substrate and bottom of chamber is tunable to 0-90 degrees ;    (3) organic solar cell comprising: three-dimensional ITO electrode; metal electrode (35); and active layer (34) forming between three-dimensional ITO electrode and metal electrode; where three-dimensional ITO electrode comprises conductive layer, and several ITO nanorods formed on conductive layer, in which ITO nanorods have adjustable length of 50-200 nm, and adjustable diameter of 30-50 nm; and further hole-transporting layer (HTL) (33) between three-dimensional ITO electrode and active layer; and    (4) fabricating organic solar cell involving: forming active layer on three-dimensional ITO electrode, where three-dimensional ITO electrode comprises conductive layer and several ITO nanorods formed on conductive layer, in which ITO nanorods have adjustable length of 50-200 nm, and adjustable diameter of 30-50 nm; forming metal electrode above active layer; and heating substrate having three-dimensional ITO electrode, active layer, and metal electrode for annealing.    DESCRIPTION OF DRAWING(S) - The figures show the three-dimensional indium-tin-oxide electrode, and the organic solar cell.    Three-dimensional ITO electrode (3)    Substrate (30)    Conductive layer (31)    ITO nanorods (32)    Hole-transporting layer (33)    Active layer (34)    Electrode (35)