Abstract
Application of small voltages in the range from 0.5 V to 1 V to an originally homogeneously Fe-doped (0.5 mol-%) TiO2 semiconductor at temperatures between 700° C and 750° C caused the formation of a p-n junction within the sample. This is indicated by a change of the U-I characteristics from a symmetrical to a diode type behavior. By inversion of the polarity of the applied voltage, the p-n junction could be removed. This process is completely reversible. The results are explained by an asymmetric change in the concentration of lattice defects, which act as dopants in addition to the extrinsic dopants, caused by the application of the voltage to the sample.
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References
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