Enhanced performance of organic photovoltaics by TiO2-interlayer with precisely controlled thickness between ZnO electron collecting and active layers

- ZnO ripple as electron-collecting layer in OPV was coated by ALD-TiO2 layer.
- We can show enhanced performance of OPVs by additional ALD-TiO2 layer.
- Defects of ZnO surface were healed by ALD-TiO2 layer.
- A thicker TiO2 (>2 nm) showed low OPV performance due to low conductivity of TiO2.
- ALD process can be beneficial for fabricating high-performing OPV.