Localized resistance measurements of wrinkled reduced graphene oxide using in-situ transmission electron microscopy

The tunable electrical properties of reduced graphene oxide (rGO) make it an ideal candidate for many applications including energy storage. However, in order to utilize the material for applications it is essential to understand the behavior of the material on the nanoscale, especially how naturally occurring phenomena like wrinkling affect the electronic transport. Here, we use a transmission electron microscope (TEM) with electrical probe in-situ holder to perform localized electrical measurements on wrinkled, supported rGO flakes. The TEM allows for observation of the local wrinkled structure of the rGO and simultaneously an electrical probe is used to perform localized resistance measurements. For these measurements, there is no correlation between the electrode distance and the measured resistance indicating that contact resistance varies and dominates the measurements. There is, however, a correlation between increasing number of wrinkles underneath the probe and decreasing resistance, indicating that the wrinkles can provide surface area for contact with the probe and thus lower the resistance. The overall resistance is on the order of single kOhm, if the contact between the probe and the rGO is optimized. These measurements give evidence that rGO with wrinkling can compete as a leading type of graphene for certain applications