Effect of TiO2 buffer layer thickness on properties of ITZO films deposited on flexible substrate

In-Sn-Zn-O (ITZO) films and a TiO2 buffer layer were deposited on PET substrates at room temperature by magnetron co-sputtering using two cathodes (DC, RF) and RF reactive sputtering at an O2 flow ratio of 2%, respectively. After applying a TiO2 buffer layer, the ITZO/TiO2 films showed an amorphous structure with a resistivity that decreased with increasing TiO2 buffer layer thickness. The mechanical properties were highest at a TiO2 thickness of 5 nm, which was confirmed by the bending test and optical microscopy images of the cracks. The resistivity and transmittance of the ITZO film with a 5 nm thick TiO2 buffer were 6.55 × 10− 4Ωcm and > 75% at 550 nm, respectively.