Photoconductivity study of Li doped homoepitaxially grown CVD diamond

Spectrally resolved photoconductivity (PC) experiments on homoepitaxially g rown, Li doped chemical vapour deposited diamond layers are presented. Om m easurements reveal two new photoconductive levels with absorption threshold s at photon energies of 0.9 eV and 1.5 eV. Due to metastable occupation, th e spectral dependence of the photoconductivity exhibits a pronounced peak. Via photoconductivity excitation experiments it could be shown that both ne w levels can be filled by photoionisation of the N donor. No correlation be tween Li content and spectral weight of photoexcitation at 1.7 eV could be observed.