Enhanced performance of multilayer MoS₂transistors encapsulated with a photoresist

We report the enhanced performance of multilayer MoS₂transistors by AZ^®5214E photoresist encapsulation. The MoS₂transistors with SiO₂bottom-gate dielectrics exhibited an average increase of 4× in the on/off-current ratio and a 50% increase in the field-effect mobility after photoresist encapsulation. The Y-function method further showed a decrease of 87% in the contact resistance and a 30% increase in the intrinsic carrier mobility, suggesting that photoresist encapsulation provides not only n-type doping but also dielectric screening. The Raman spectra of the photoresist-encapsulated MoS₂also suggest n-type doping, which may be due to the electropositive hydroxyl groups in the photoresist. The operation of the photoresist-encapsulated MoS₂transistors remained stable in ambient air for at least one month. These results demonstrate that simple photoresist encapsulation can be an effective performance booster of MoS₂and other transition metal dichalcogenides transistors.