A method of preparation of semiconductor material. The method includes: adding an organic substance containing a benzene ring and dodecacalcium hepta-aluminate (12CaO.7Al2O3 or C12A7) to a test tube, and sealing the test tube; heating the test tube to a temperature of 200-300° C., and holding the temperature for 1 to 3 hours; and continuously heating the test tube to a temperature of 900-1300° C., and holding the temperature for 10-120 hours.