진공증착된 비정질 규소의 상태밀도 결정

Abstract

진공증착된 비정질 규소는 Plasma deposition에 의해 제작된 시료보다 gap內에 局在化된 defect states가 많기 때문에 상온의 전기 전도도(σRT)가 크다. gap內의 상태밀도, N(ε),가 field effect실험에 의해 0.4eV<(ε??-ε)<0.9eV의 에너지 영역에서 결정되었다.

진공증착된 비정질 규소의 N(ε??)-ε??는 Fermi준위-가 10??㎝??eV??로 plasma deposition에 의해 제작된 시료보다 크게 나타났다. hydrogenation된 시료는 N(ε)가 낮게 나타났는데 T??=350℃에서 가장 작았다. N(ε)는 저온에서 variable range hopping의 여러가지 이론적인 모형에 대한 결과의 分析에 사용되었다.

The room temperature conductivity (σRT) of the evaporated a-Si is higher than that of the plasma deposited one, because of the many localized defect states in the gap. The density of states in the gap, N(ε), was determined in the energy range 0.4eV<(ε??-ε)<0.9eV using the field effect experiment. N(ε) of the evaporated a-Si, where ε?? is Fermi level, was about 10??㎝?? eV?? and was larger than that of plasma deposited sample. N(ε) was lowered by the hydrogenation and was minimized at T??=350℃. The knowledge of N(ε) was used in the analysis of the results of the variable range hopping at low temperature using various theoretical models.

The room temperature conductivity (σRT) of the evaporated a-Si is higher than that of the plasma deposited one, because of the many localized defect states in the gap. The density of states in the gap, N(ε), was determined in the energy range 0.4eV<(ε??-ε)<0.9eV using the field effect experiment. N(ε) of the evaporated a-Si, where ε?? is Fermi level, was about 10??㎝?? eV?? and was larger than that of plasma deposited sample. N(ε) was lowered by the hydrogenation and was minimized at T??=350℃. The knowledge of N(ε) was used in the analysis of the results of the variable range hopping at low temperature using various theoretical models.