OPTICAL, ELECTRICAL AND STRUCTURAL INVESTIGATIONS OF THE TRANSITION FROM AMORPHOUS TO MICROCRYSTALLINE SILICON

Optical and electrical properties were correlated with structural inve stigations during the amorphous-to-microcrystalline phase transition o f magnetron-sputtered silicon thin films. The optical characterization was carried out using the Tauc formalism, and the electrical transpor t phenomena were studied by means of thermal activated conductivity me asurements. The absorption measurements show a sharp increase of the g rain boundary states corresponding to a bent Tauc plot during the crys tallization. This increase of grain boundary states leads to a drastic drop of the activation energy of the conductivity to zero. A new mode l of combined grain boundary states is introduced to explain the elect ric and optical behavior in such new microcrystalline materials.