the following table 1 and fig2 fig1 is a graph illustrating a rietveld profile of bicuote by comparison between an x ray diffraction pattern and a theoretical pattern of a structural model referring to fig1 it was found that the measured pattern was consistent with the calculated pattern according to the results of table 1 thus the material obtained according to the reference example was identified as bicuote as shown in fig2 this bicuote compound semiconductor exhibits a natural superlattice structure that a cu 2 te 2 layer and a bi 2 o 2 layer are repeated along a c crystal axis bi 1 x cuote was synthesized in the same way the reference example except that a mixing amount of each raw powder was controlled according to the following table 2 for a partial deficiency of bi in bicuote the mixing amount of each raw powder for synthesis is as follows unit g bicu 1 y ote was synthesized in the same way the reference example except that a mixing amount of each raw powder was controlled according to the following table 3 for a partial deficiency of cu in bicuote the mixing amount of each raw powder for synthesis is as follows unit g bi 0 96 cuo 0 94 te was synthesized in the same way the reference example except that a mixing amount of bi 2 o 3 was relatively reduced for a partial deficiency of both bi and o a mixing amount of each raw powder for synthesis is as follows unit g and test sections of the compounds according.