Bilayer phosphorene stability under MoS2 passivation

#Black Phosphorus #MoS2 #Field-Effect Transistor

Our research group has delvied into the stability of bilayer phosphorene under MoS2-passivation. Despite the unique properties of black phosphorus (BP) and phosphorene, such as high carrier mobility and in-plane anisotropy, their stability has been compromised due to significant crystal deterioration upon exposure to oxygen and water. We are investigating the chemical stability of MoS2-passivated BP or bilayer phosphorene using field-effect transistor (FET) and phototransistor effects. Our study spans four thicknesses of MoS2-passivated BP FETs to understand the effects of the MoS2 passivation layer on device stability and electrical characteristics under various conditions. We discovered that trilayer MoS2 passivation enhances the photoresponse of a 2L-phosphorene optoelectronic heterojunction by 78% without gate bias and reduces the photoluminescence quantum yield of the phosphorene bilayer crystal by 29%. This reduction can be attributed to the difference in absorption in the BP layer induced by the interference color effect generated by the presence of the thin MoS2 layer and a built-in electric field at the BP-MoS2 p-n interface. Our findings suggest that 2D MoS2 thin passivation layers provide specific chemical stability and electro-optical enhancement for transparent, flexible BP electronic and optoelectronic devices.

A study of bilayer phosphorene stability under MoS2 passivation.

Youngwoo Son, Daichi Kozawa, Albert Tianxiang Liu, Volodymyr B Koman, Qing Hua Wang, Michael S Strano. (*: equal contribution)

2D Materials, 4, 025091 (2017). 10.1088/2053-1583/aa6e35