Band offset analysis at two-dimensional molybdenum disulfide/boron nitride heterointerface for non-volatile memory applications

초록

Van der Waals nanomaterials have been regarded as promising candidates with outstanding electrical and optoelectronic properties for advanced semiconductor and photoelectronic applications. In this work, we investigate the band offsets at the multilayered molybdenum disulfide (ML-MoS2)/boron nitride (BN) van der Waals heterointerface using high-resolution X-ray photoelectron spectroscopy. The crystalline structures and optical Raman responses of the ML-MoS2, BN, and ML-MoS2/BN van der Waals heterointerface were studied using X-ray diffraction and Raman spectroscopy. The type I straddling gap with a valence band offset (1.33 eV) and conduction band offset (3.14 eV) at the heterointerface was confirmed. Based on the defined band offsets, a nonvolatile NAND flash memory device with van der Waals materials was designed, featuring a gate stack consisting of the ML-MoS2/BN heterostructure. The proposed non-volatile memory device exhibited excellent memory operation with gradual charge trapping and de-trapping over multiple pulse cycles during the program and erase processes. Considering that the modulation of band offsets between the channel and tunneling layer can improve memory operations, determining the band offsets plays an essential role in developing highperformance semiconductor devices. Thus, this work presents the new value of the band alignment studies and provides valuable knowledge for designing future semiconductor and optoelectronic applications.

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