NOVELTY - Fabricating a nanostructure, comprises: (a) forming an electrically conductive substrate having at least one nano-pit; and (b) depositing at least one material along the nano-pit to form a nano structure.    USE - The method is useful for fabricating a nanostructure which is a nanostructured electrode that is useful: for constructing a nanobattery (all claimed); and in photovoltaic devices.    ADVANTAGE - The method: utilizes the conductive substrate having the nano-pit which is a nano-pitted metal film serving as both current collector and growth substrate for the nanostructure electrode (claimed); and provides the nanobattery or thin film battery having increased performance.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) fabricating a nano-pitted substrate, comprising: (a1) chemically polishing a metal thin film in a first acid for a predetermined amount of polishing time; (a2) oxidizing the metal thin film with an acidic solution in an electrochemical cell at a predetermined temperature and a first predetermined voltage potential and for a predetermined amount of oxidation time; (a3) decreasing the first predetermined voltage potential at a predetermined step-down rate to a second predetermined voltage potential; and (a4) etching the oxidized metal thin film with a second acid to form the nano-pitted substrate; and    (2) constructing a nanobattery, comprising: (b1) forming a nanostructured anode electrode on a nano-pitted anode substrate, where the nano-pitted anode substrate serves as both an anode current collector and an anode growth substrate for the nanostructured anode electrode; (b2) forming a nanostructured cathode electrode on a nano-pitted cathode substrate, where the nano-pitted cathode substrate serves as both a cathode current collector and a cathode growth substrate for the nanostructured cathode electrode; and (b3) forming an electrolyte layer intermediate of the nanostructured anode cathode and the nanostructured anode to construct the nanobattery.