MODEL OF HF HOPPING PHOTOCONDUCTIVITY OF DOPED SI

The phenomenological model of HF hopping photoconductivity through exc ited metastable states of impurities in semiconductor is considered. P olarization conductivity is produced by variation of majority and mino rity ion pair dipols due to electron transitions between ionized and e xcited atoms of majority impurity. It is established, that important c ontribution in HF conductivity is due to complexes consisting of excit ed and ionized atoms of majority impurity and minority impurity ion. C omplexes are created by capture of photocarriers on dipoles and by dri ft of majority impurity ions in electric field of minority impurity io ns. The simple expressions are obtained for dependences of HF hopping photoconductivity on excitation intensity, majority and minority impur ity concentration and temperature. The absolute value of HF photocondu ctivity is estimated. It is shown that model is in a satisfactory agre ement with experimental results obtained for extrinsic photoconductivi ty in Si doped with III and V group impurities under microwave bias.