Solar cells are nowadays one of the most important issues that facing scientists. This is because they represent the best alternative that can replace petrol fuel. This encourages scientists to do intensive work to increase the efficiency of solar cells. Motivated by this urgent need for high-efficiency solar cells this work was done by preparing 5 samples of carbon doped with Aluminum oxide with different molar concentrations (0.1,0.3,0.5,0.7,0.9). The aim of this work is to characterize these samples to see how they can used as solar cells. The crystal and nanostructure have been characterized by using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. The optical and electrical properties were characterized using an ultraviolet-visible spectrometer. The performance of a solar cell was tested using a simple electric circuit. The results of NixAL2(1-x)O4 samples indicate that the decreasing of Ni concentration (X) decreases the energy gap while the nanocrystal size, d-spacing, mass density, absorption coefficient, and solar cell efficiency increase. All the solar cell samples of this specimen exhibited a voltage of 1.184mV, an open-circuit voltage of 1.440mV, a fill factor of 0.73, and an efficiency range from 1.8642% up to 2.2460% according to the different concentrations.