THE IRON STATES IN CD1-XFEXTE IN THE FUNDAMENTAL GAP ENERGY-RANGE

The reflectivity, absorption, photoconductivity, and cathodoluminescen ce spectra for Cd1-xFexTe (0 less than or equal to x less than or equa l to 0.05) at 300 and 77 K are investigated. The measurements are carr ied out in the fundamental gap energy range. From the analysis of the experimental results, the energy positions and properties of Fe states in the CdTe matrix in the fundamental gap region are presented and di scussed. It is concluded that the increase of the width of the fundame ntal,gap with the change of temperature from 300 to 77 K leads mainly to the rise of the energy distance between the donor-like iron state ( 5)E and the bottom of the conduction band, whereas the energy distance between the iron state (5)E and the top of the valence band remains u nchanged. The increase of the fundamental gap value with the decrease of temperature changes the energy positions of the excitation iron sta te T-3(1) With respect to the bottom of the conduction band. Energy po sitions of iron stales in the fundamental gap energy region as well as the increase of the energy width and density of these states with the rise of the iron concentration in Cd1-xFexTe are reflected in the res ults obtained with the use of different experimental methods.