TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The semiconductor nanostructures comprise silicon nanowires, germanium nanowires, group III-V compound nanowires, or group II-VI compound nanowires. The transparent conducting substrate or the transparent electrode comprises indium tin oxide. The transparent substrate comprises glass substrate, plastic substrate, or quartz substrate. In the solar cell one end of the semiconductor nanostructure connects to a metal electrode, the other end of the semiconductor nanostructure connects to a transparent electrode via the conducting polymer and an insulating layer is arranged between the metal electrode and the conducting polymer.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The solvent is: an organic solvent (acetone, methanol or isopropanol), where the surface of the semiconductor nanostructures is modified to be hydrophobic; or water, where surface of the semiconductor nanostructures is modified to be hydrophilic.    TECHNOLOGY FOCUS - POLYMERS - Preferred Method: In the method: a metal-assisted chemical etching method or a dry etching method is employed to etch the semiconductor substrate and form the semiconductor nanostructures where the density of the semiconductor nanostructures is greater than or equal to 20 pieces/ mu m2; the step for producing the semiconductor nanostructures comprises a vapor-phase epitaxy method or a liquid-phase epitaxy method; the step to adhere the conducting polymer to the semiconductor nanostructures by capillary effect comprises dissolving the conducting polymer in a solvent thus forming a conducting polymer solution (25), modifying the surface of the semiconductor nanostructures to be hydrophilic or hydrophobic, according to the character of the solvent, inserting the top portions of the semiconductor nanostructures into the conducting polymer solution, which then adheres to the surface of the semiconductor nanostructures by capillary effect and heating the conducting polymer solution to dry the conducting polymer solution; the conducting polymer solution is first coated on a transparent conducting substrate or a transparent electrode (24) of a transparent substrate (23), and then the top portions of the semiconductor nanostructure are inserted into the conducting polymer solution, under a condition that the conducting polymer solution is wet and moveable, where coating is performed by a spin coating method or a dip coating method; the metal-assisted chemical side-etching method is used for side-etching the root portion of each semiconductor nanostructure, before the step of adhering the conducting polymer; after the formation of the semiconductor nanostructure/conducting polymer heterojunctions, further comprises exerting a mechanical force to detach the semiconductor nanostructures from the semiconductor substrate, forming an insulating layer to cover the conducting polymer but expose the semiconductor nanostructures and forming a metal electrode to cover the insulating layer and the semiconductor nanostructures; and before the formation of the semiconductor nanostructure/conducting polymer heterojunctions further comprises transferring the semiconductor nanostructures on metal electrode in a physically manner and forming an insulating layer to cover the metal electrode but expose the semiconductor nanostructures. Preferred Components: The conducting polymer is poly(3,4-ethylenedioxy thiophene), poly(styrene sulfonate), poly(3-hexylthiophene), 6,6-phenyl-C61-butyric acid methyl ester (all preferred), polyaniline, phthalocyanine, poly-tris(methyl)-silicon-cyclooctatetraene, tetraphenylporphyrin or 4-tricyanovinyl-N,N-diethylaniline. EXAMPLE - No suitable example given.