Band offsets of TiZnSnO/Si heterojunction determined by x-ray photoelectron spectroscopy

X-ray photoelectron spectroscopy (XPS) was utilized to measure the valence band offset (Delta E-V) of the TiZnSnO (TZTO)/Si heterojunction. TZTO films were deposited on Si (100) substrates using magnetron sputtering at room temperature. By using the Zn 2p(3/2) and Sn 3d(5/2) energy levels as references, the value of Delta E-V was calculated to be 2.69 +/- 0.1 eV. Combining with the experimental optical energy band gap of 3.98 eV for TZTO extracted from the UV-vis transmittance spectrum, the conduction band offset (Delta E-C) was deduced to be 0.17 +/- 0.1 eV at the interface. Hence, the energy band alignment of the heterojunction was determined accurately, showing a type-I form. This will be beneficial for the design and application of TZTO/Si hybrid devices. (C) 2014 AIP Publishing LLC.