NOVELTY - The nitride solar cell comprises a set of indium gallium nitride thin films and an active layer formed with a hole and an electron with an incoming solar light, where the hole and electron move to a first nitride semiconductor layer or a second nitride semiconductor layer to produce the electric power. A gallium nitride thin film is formed between a barrier and the second nitride semiconductor layer, where the first nitride semiconductor layer has first energy level, and the second nitride semiconductor layer has second energy level that is greater than the first energy level.    USE - The nitride solar cell is useful in a semiconductor light emitting device and high frequency and power device.    ADVANTAGE - The cell maintains good crystallization even if the indium gallium nitride thin films are grown in the various hundreds nanometer so that the photoelectric conversion efficiency of the cell is increased. The energy level of the active layer is controlled according to the thickness of the indium gallium nitride thin films so that absorption of the solar energy is increased.    DETAILED DESCRIPTION - The nitride solar cell comprises a set of indium gallium nitride thin films and an active layer formed with a hole and an electron with an incoming solar light, where the hole and electron move to a first nitride semiconductor layer or a second nitride semiconductor layer to produce the electric power. A gallium nitride thin film is formed between a barrier and the second nitride semiconductor layer, where the first nitride semiconductor layer has first energy level, and the second nitride semiconductor layer has second energy level that is greater than the first energy level. The active layer and the indium gallium nitride thin films have the thickness of 0.1-10 nm, and the gallium nitride thin film has a thickness of 0.3-30 nm. The first nitride semiconductor layer is doped with the p-type impurity, and the second nitride semiconductor layer is doped to n-type impurity. The energy level of the active layer is controlled according to the thickness of the indium gallium nitride thin films, where the active layer has the predetermined wavelength band corresponding to the controlled energy level. An INDEPENDENT CLAIM is included for a method for fabricating a nitride solar cell.