Method for Direct Determination of the Effective Correlation Energy of Defects in Semiconductors: Optical Modulation Spectroscopy of Dangling Bonds

Abstract

The optical modulation technique is used for direct determination of energy levels and the effective correlation energy ${U}_{\mathrm{eff}}$ of dangling-bond defects. With an accuracy of 0.1 eV we found for the dangling-bond defect in $a$-Si: H, ${U}_{\mathrm{eff}}=0.5$ eV; in $a$-${\mathrm{As}}_{2}$${\mathrm{S}}_{3}$, ${U}_{\mathrm{eff}}=\ensuremath{-}1.0$ eV; in ${\mathrm{As}}_{2}$${\mathrm{Se}}_{3}$, ${U}_{\mathrm{eff}}=\ensuremath{-}0.7$ eV; and in trans-${(\mathrm{CH})}_{x}$, ${U}_{\mathrm{eff}}=0.95$ eV.