Near-field photocurrent nanoscopy on bare and encapsulated graphene

摘要: Optoelectronic devices utilizing graphene have demonstrated unique capabilities and performances beyond state-of-the-art technologies. However, requirements in terms of device quality uniformity are demanding. A major roadblock towards high-performance nanoscale variations the properties, impacting their macroscopic behaviour. Here we present apply non-invasive optoelectronic nanoscopy to measure optical electronic properties locally. This is achieved by combining scanning near-field infrared with electrical read-out, allowing photocurrent mapping at length scales tens nanometres. Using this technique, study impact edges grain boundaries on spatial carrier density profiles local thermoelectric properties. Moreover, show that technique can readily be applied encapsulated devices. We observe charge build-up near demonstrate a solution issue.