Photovoltaic Field-Effect Transistors Using a MoS₂ and Organic Rubrene van der Waals Hybrid

A several-layer n-type MoS₂ was partially hybridized with an organic crystalline p-type rubrene nanosheet through van der Waals interactions to fabricate a two-dimensional (2-D) lateral-type n-p heterojunction optoelectronic device. The field-effect transistors (FETs) using lateral-type MoS₂/rubrene hybrids exhibited both gate-tunable diode and anti-ambipolar transistor characteristics. The FET devices show the coexistence of n-type states, p-type states, and off-states controlled by the gate bias. From the photocurrent mapping experiments, the gate-bias-dependent photovoltaic effect was observed from the heterojunction regions of the MoS₂/rubrene FETs. Furthermore, the photovoltaic FETs were successfully operated by light irradiation without applying source-drain bias and controlled using gate bias. These devices represent new solar-energy-driven 2-D multifunctional electronic devices.