MEASUREMENT OF DENSITY OF THE GAP STATES IN a-Si:H BY THE NORMALIZATION OF PHOTOCONDUCTIVITY

【摘要】 <正> The spectra of the optical absorption coefficient in low absorption region are obtained by using anormalization procedure for the photoconductivity spectra.The results are explained in terms of theoptical transition of electrons from localized states in the exponential valence band tail and in danglingbond states 1.0 eV below the conduction band edge to extended conduction band states.Then thedensity of the gap states below the Fermi level E_F is obtained.From the investigation ofrecombination kineties,the average density of,the gap states over the range of(F_Fn-E_F)and thedensity of the gap states above the Fermi level E_F are obtained.These indicate that the width of theconduction band tail is smaller than that of the valence band tail.更多还原

【Abstract】 The spectra of the optical absorption coefficient in low absorption region are obtained by using a normalization procedure for the photoconductivity spectra.The results are explained in terms of the optical transition of electrons from localized states in the exponential valence band tail and in dangling bond states 1.0 eV below the conduction band edge to extended conduction band states.Then the density of the gap states below the Fermi level E_F is obtained.From the investigation of recombination kineties,the average density of,the gap states over the range of(F_Fn-E_F)and the density of the gap states above the Fermi level E_F are obtained.These indicate that the width of the conduction band tail is smaller than that of the valence band tail.更多还原