Growth and characterization of low cost, and high efficiency micro- and nanostructured p-n heterojunction solar cells through eutectic solidification are provided. Eutectic solidification results in self-assembly of lamellar or rod-like domains with length scales from hundreds of nanometers to micrometers that can be used for efficient extraction of minority carriers in metallurgical-grade materials. The material having a eutectic or near-eutectic composition can be used in making a low-cost and efficient inorganic solar cell.