Author/Authors :
Verbitskaya، نويسنده , , E. V. Eremin، نويسنده , , V. and Ivanov، نويسنده , , A. and Strokan، نويسنده , , N. and Vasilèv، نويسنده , , V. and Markov، نويسنده , , A. and Polyakov، نويسنده , , A. and Gavrin، نويسنده , , Dina V. and Kozlova، نويسنده , , Yu. and Veretenkin، نويسنده , , E. and Bowles، نويسنده , , T.J.، نويسنده ,
Abstract :
The results on electrical characteristics and charge collection efficiency in the detectors from bulk SI GaAs developed as a material for solar neutrino spectroscopy are presented. SI GaAs crystals were grown by the Czochralski method. The changes in the stoichiometric components are permanently controlled. It is shown that the performance of GaAs p+–i–n+ structures provided the range of operational reverse voltage up to 1 kV. Measurement of deep level spectra and their analysis reveal the dominant deep levels – hole traps Ev+0.51 and +0.075 eV in GaAs grown from stoichiometric and nonstoichiometric melts, respectively. Investigation of carrier transport properties and bulk homogeneity evinced in charge collection efficiency has shown advantageous results for SI GaAs grown from stoichiometric melt. The reduction of carrier transport parameters and charge collection efficiency in GaAs grown from nonstoichiometric melt is analyzed taking into consideration formation of the hole trap Ev+0.075 eV, presumably assigned to Ga antisite and its influence on the concentration of the ionized deep donor level EL2+.
