Study On The Growth Of V-Doped Cd_0.9Mn_0.1Te Crystal Of Defects And Photoelectric Performance

Cd1-x Mnx Te is a typical II-VI compound semiconductor.In the 1980 s,Researchers began to study Cd1-x Mnx Te materials.Because of the existence of the paramagnetic Mn2+ and the exchange interaction of electros,p state and s state.at room-temperature,this coupling interaction can produce a variety of optical properties which make this material lots of applications,Such as,optical isolator,semiconductor laser devices,electro-optic switch.In recent years,people began to research the wide band gap properties of Cd1-x Mnx Te,Indoped Al and Sn Cd1-x Mnx Te crystal has been used in energy spectrum detectors.Indoped In Cd1-x Mnx Te crystal is used in the high-resolution spectrometer processing system.At present,Cd1-xMnx Te materials are widely used in the infrared detector,x-ray and gamma-ray detectors.Compared with Cd1-x Znx Te materials,in some aspect,such as,the wide forbidden band,the high average atomic number and the crystallization quality.so the Cd 1-x Mnx Te crystal is expected to replace the Cd1-x Znx Te materials in the application of x/? radiation ray detector.The high resistivity is one of the key indicators of nuclear radiation detector.By using traditionna methed.It is difficult to obtain high quality half insulating crystals.The main reason is that in high temperature,the vapor of Cd is the highest among these elements.The Cd component evaporation makes a large number of point defect to reduce the resistivity of Cd1-x Mnx Te crystals.People improved the resistivity of Cd1-x Mnx Te crystals mainly by doping methed.Zhang et al.using the bridgman method to grow the In doped Cd1-x Mnx Te crystal,with the resistivity is 108~109 ?·cm,In this paper,we grow V doped Cd1-x Mnx Te single crystal(the concentration of V is 1017cm-3)by vertical Bridgeman methed feom Te resolution.By designing the doping concentration and optimizing growth process parameters,we successfully obtained Cd0.9Mn0.1Te:V single crystal with the size of ?30mm×90mm.Then the quality of crystal,defects and photoelectric performance were evaluated.(1)Crystalline quality evaluation:XRD powder diffraction shows that V doping does not only affect the crystal structure,but improve the crystal,s quality;Electron probe microanalysis shows that the distribution of Mn in crystal,s axial direction.(2)Defect studies:the infrared images show tow kinds of Te inclsion exist in this crystal,namely square and hexagonal,and Te inclusions,s density can be read as5.1×104,1.4×103,and 6.0 ×105(Unit:Density/cm-2),in the tip,middle and the end pant,respectirely.T the results show that the desity of the middle part of this ingot is lower.Using Scanning Electron Microscopy to observe the existence of twin and study the relationship between the twins and Te inclusions:the results show that the Te inclusions all surround the twins and in linear array.(3)The photoelectric properties :Hall effect shows that the Cd0.9 Mn0.1 Te: V is P type semiconductor,The results of I-V test how that the resistivity(?·cm)in the ingot,s head?middle?tail of the crystal is 1.446×1010,4.123×1010,2.012×1010,respectirely.All the results preved than V doping has improved the resistivity of the crystal and the crystallization quality,especially in the middle part of this ingot.and The Infrared Transmittance of crystal is 63%,closing to the theoretical value.The result of PL spectra of crystal shows that the(D0,X)Peak is in the dominant position,its binding energy is 12.11 me V,In summary,it can be illustrated that the desity of the defects are lower than non-V doping from the sharp of(D0,X)peak and the narrow full width.Half Maximum(FWHM).Therefore,we can say that V doping has a positive effect on the great improvement in crystal's quality.