Detailed characterization of deep centers in CdTe: Photoionization and thermal ionization properties

Electronic properties of four defect centers (designated as E7, E8, I, and IV) in A1‐doped n‐CdTe single crystals annealed under various Cd vapor pressures ( pCd) have been investigated by a combined use of photocapacitance, deep level transient spectroscopy (DLTS), and thermally stimulated capacitance techniques. Electron trap E7 at Ec−0.68 eV, a dominant deep defect center in samples quenched after annealing under high pCd, has shown a strong interaction with the lattice vibrations (S≳30, S: electron‐phonon coupling parameter). The photoionization threshold energy for electrons E0n for the purely electronic transition has been estimated to be larger than 1.30 eV. Temperature dependence of the capture cross section for electrons σtn has been found to be very weak. The configuration coordinate diagram for E7 has suggested that E7 will nonradiatively capture the free electron. On the other hand, recombination center E8 at Ec−0.74 eV, a dominant deep defect center in samples annealed under low pCd, has show...

[1]  S. Pantelides.  The electronic structure of impurities and other point defects in semiconductors , 1978 .

[2]  L. Ledebo,et al.  Photo-ionization of deep impurity levels in semiconductors with non-parabolic bands , 1975 .

[3]  C. Sah,et al.  Photoionization of Electrons at Sulfur Centers in Silicon , 1971 .

[4]  A. Tepore,et al.  Characterization of CdTe with photoelectronic techniques , 1977 .

[5]  J. Pautrat.  Electric field and impurity concentration effects on the ionization energy of impurities. Application to acceptors in ZnTe , 1980 .

[6]  A. Mircea,et al.  Detailed electrical characterisation of the deep Cr acceptor in GaAs , 1980 .

[7]  R. Triboulet,et al.  Temperature dependance of the fundamental absorption edge in CdTe , 1973 .

[8]  J. M. Herman,et al.  Photoionization cross sections of holes at zinc centers in silicon , 1973 .

[9]  M. Caillot.  Low temperature annealings of the defect created by 1.5 MeV electron irradiation in n-type CdTe , 1972 .

[10]  M. Lorenz,et al.  Some Properties of a Double Acceptor Center in CdTe , 1964 .

[11]  P. Höschl,et al.  Preparation of cadmium telluride single crystals for nuclear detectors , 1975 .

[12]  Kun Huang,et al.  Theory of light absorption and non-radiative transitions in F-centres , 1950, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[13]  D. Marple,et al.  Effective Electron Mass in CdTe , 1963 .

[14]  H. Vydyanath,et al.  The defect structure of CdTe: Hall data , 1975 .

[15]  P. Siffert,et al.  Determination of deep levels in semi-insulating cadmium telluride by thermally stimulated current measurements , 1975 .

[16]  C. Canali,et al.  Transient and steady state space-charge-limited current in CdTe , 1975 .

[17]  L. Samuelson,et al.  Optical transitions via the deep O donor in GaP. I. Phonon interaction in low-temperature spectra , 1978 .

[18]  R. Čumpelík,et al.  Thermostimulated currents in n-type CdTe single crystals , 1969 .

[19]  M. Lorenz,et al.  Shallow and deep acceptor states in CdTe , 1963 .

[20]  F. J. Bryant,et al.  Atomic displacements and the nature of band edge radiative emission in cadmium telluride , 1968 .

[21]  F. Smith.  Electrically active point defects in cadmium telluride , 1970 .

[22]  Tsunehiro Tanaka,et al.  Photocapacitance studies of the C1-related deep center in CdTe , 1981 .

[23]  P. Siffert,et al.  Polarization in Cadmium Telluride Nuclear Radiation Detectors , 1976, IEEE Transactions on Nuclear Science.

[24]  D. V. Lang,et al.  Capacitance Transient Spectroscopy , 1977 .

[25]  W. Zachariasen,et al.  Low temperature lattice transformation of HfV2 , 1972 .

[26]  H. Grimmeiss,et al.  Deep Level Impurities in Semiconductors , 1977 .

[27]  F. J. Bryant,et al.  Threshold Energy for Atomic Displacement in Cadmium Telluride , 1967, May 1.

[28]  D. Shaw,et al.  Evidence of a Doubly Ionized Native Donor in CdTe , 1968 .

[29]  D. Lang,et al.  Nonradiative capture and recombination by multiphonon emission in GaAs and GaP , 1977 .