Novel structures of photovoltaic cells (also called as solar cells) are provided. The cells are based on nanoparticles or nanometer-scaled wires, tubes, and/or rods, which are made of electrical materials covering semiconductors, insulators, and also metallic in structure. These photovoltaic cells have large power generation capability per unit physical area over the conventional cells. These cells will have enormous applications such as in space, commercial, residential and industrial applications.

A method of forming a wavelength detector that includes forming a first transparent material layer having a uniform thickness on a first mirror structure, and forming an active element layer including a plurality of nanomaterial sections and electrodes in an alternating sequence atop the first transparent material layer. A second transparent material layer is formed having a plurality of different thickness portions atop the active element layer, wherein each thickness portion correlates to at least one of the plurality of nanomaterials. A second mirror structure is formed on the second transparent material layer.

Disclosed are an ink composition for manufacturing a light absorption layer of solar cells and a method of manufacturing a thin film using the same. Particularly, an ink composition for manufacturing a light absorption layer of solar cells including core-shell structure nanoparticles including a core including a copper (Cu)-containing chalcogenide and a shell including a zinc (Zn)-containing chalcogenide; and tin (Sn)-containing bimetallic or intermetallic metal nanoparticles, or a tin (Sn)-containing chalcogenide nanoparticles, dispersed in a solvent, and a method of manufacturing a thin film using the same are disclosed.