Recent advances in the fabrication of two-dimensional transition metal dichalcogenide (2D-TMD) semiconductors opened exciting possibilities in a wide range of applications in electronics, photonics, and optoelectronics. Especially, few layers molybdenum disulphide (MoS2) have attracted tremendous interest as channel material for overcoming the short-channel effects in ultra-scaled field-effect transistors (FETs). Here we present the study of the energy band alignment at MoS2/SiO2 interface using internal photoemission (IPE) spectroscopy. A clear understanding of the energy alignment of electron bands is essential for the design of MoS2 based devices. For example, in electrical measurements such as current, capacitance, etc, a high lateral resistivity in few layer semiconductor (or FL-MoS2) films impairs lateral measurements. Therefore, here we employed IPE that is capable to characterize the energy band alignment also on discontinuous films through observation of electron transport in the direction normal to the interface. In this work, few layer MoS2 films were grown on SiO2 (50nm)/Si using ambient pressure chemical vapor deposition (AP-CVD) from different metal precursors and with the use of different (i) organic (PTAS) and (ii) inorganic promoters, namely Na (OH), KCl and KI. The so-grown MoS2 samples were analysed using IPE, to determine the electron energy position of the semiconductor valence band (VB) of MoS2 relative to the reference level of the conduction band (CB) of SiO2.(i) Firstly, using IPE spectroscopy, Powell’s plots of IPE quantum yield spectra for CVD grown 6L-MoS2 from PTAS seed promoter were built with …