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Depth-dependent electronic band structure at the Au/CH3NH3PbI3-xClx junction
Myung Joo Cha1, Yu Jung Park1, Jung Hwa Seo1
1Department of Materials Physics, Dong-A University, Busan, 49315, Republic of Korea. seojh@dau.ac.kr.
Abstract:
The electronic properties of the interface between Au and organometallic triiodide perovskite (CH3NH3PbI3-xClx) were investigated by ultraviolet photoelectron spectroscopy (UPS) and X-ray photoemission spectroscopy (XPS). CH3NH3PbI3-xClx films were prepared on Au surfaces by spin casting with various concentrations to control the film thickness. Their morphology was examined by atomic force microscopy (AFM). CH3NH3PbI3-xClx films exhibited a maximum valence band edge of 5.91 eV. The energy levels shifted downward by 0.26 eV with a perovskite coverage of 116.3 nm, indicating that band bending occurs at the interface. The observed energy level shift indicates an interface dipole at the Au/CH3NH3PbI3-xClx junction. These findings contribute to the understanding of how perovskite materials function in electronic devices and aid in the design of new perovskite materials.
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