六方InN薄膜的载流子输运特性研究

Carrier transport characteristics in hexagonal InN thin films

通过变温 (10— 30 0K)暗电流特性研究了射频磁控溅射法生长在半绝缘GaAs (111)衬底上的六方InN薄膜的载流子输运过程 .在晶界势垒模型的基础上 ,发现InN薄膜的电导特性取决于材料内部的晶界势垒高度 ,载流子输运特性是由于空穴在晶界处的积累决定的 .从获得的InN薄膜晶界势垒高度 ,可以估算出InN薄膜内的缺陷浓度 ,结果与显微拉曼散射实验结果相一致 ,这进一步说明了晶界势垒模型适用于描述InN中的载流子输运特性 .

The dark current characteristics of hexagonal InN thin films grown by rf magnetron sputtering on semi-insulating GaAs (111) substrates have been investigated systematically at different temperatures from 10 K to room temperature. The carrier transport characteristics of the InN thin films have been explained successfully on the basis of a grain-boundary barrier model, where the accumulation of holes at the grain boundaries has been found to play a key role. From the yielded height of the grain-boundary barrier, we can estimate the trap concentration in the InN thin films, which are in agreement with the micro-Raman results. The results give clear evidence that the grain-boundary barrier model can be used to interpret the carrier transport characteristics in InN thin films.