AB-INITIO CALCULATION OF G-VALUES OF ESR CENTERS IN ALPHA-SI-H BY CLUSTER-MODELS

ESR centers in several silicon clusters are calculated by the ab initio molecular orbital method using perturbation theory. Dangling bonds (D-0) are modeled by clusters with 4-22 silicon atoms. The calculated g-values for the dangling bonds due to a hole or an electron with a Si-Si bond, and charged dangling bonds (D+ + e(-), D- + h) are also modeled by 4-20 silicon atoms, and their g-values are also compared with ESR measurements of doped a-Si:H and LESR measurements of undoped a-Si:H. It is shown that the charged bond model is consistent with experimental results.