Hybrid perovskite transistor: performance limitations and solution approach

Perovskite has been a material of extreme interest due to its dramatic improvement in performance of photovoltaic solar cells. The electronic and transport properties of perovskites have desired properties that can be used as the channel for field effect transistors (FET). However, only few reports are available on the successful fabrication of perovskite transistor (PFET) and those had limited performance. We have identified two main performance limitations of PFET from careful review of published literature. These are poor drain current and high threshold voltage (V_th). In this report, we investigated behind the limitations. Our capacitance-voltage study on perovskite/dielectric/conductor structures with different types of dielectric materials reveal that the V_th can be significantly reduced to operate PFET by selection of a suitable dielectric. Comparative I-V study of lateral vs vertical direction perovskite films were performed in dark and light. We identified that, the lateral resistivity is substantially larger than vertical counterpart which causes the poor drain current. This difference is attributed to the higher number of grain boundaries along the lateral direction as confirmed by cross-sectional SEM analysis