Plyaka S. Charge transport in the sillenite crystals.

The object of investigation is optical, electrical and photoelectrical properties of the sillenite type crystals. The aim of the work is the determination of common legitimacy of the charge transport for the films and single crystals Bi12SiO20 (BSO) and Bi12GeO20 (BGO). The methods of investigations are the volt-current measurements, time-of-flight method, electrical, photoelectrical and optical absorption measurements. It has been shown that mobiles electrons and holes are dark charge carriers in sillenites. The crystals are strongly compensated. By the charge of the impurity concentration of 3-d elements it is possible to charge the level of compensation. The introduction of the vanadium ions results in lighten of germanium sillenite crystals in the range of the absorption shoulder (hn >2.2 eV). The correlation between the absorption value and the compensation level observed. The higher compensation the higher absorption. On the basis of the qualitative analysis of obtained results it is possible to explain optical? Electrical and photoelectrical properties of sillenite crystals by the model of strongly compensated semiconductors.