Low temperature preparation of W-doped In2O3 transparent electrodes for p-i-n structured perovskite solar cells

W-doped In2O3 (IWO) films prepared by reactive plasma deposition (RPD) technique at 150 °C have been studied to replace Sn-doped In2O3 (ITO) serving as transparent electrodes for p-i-n structured perovskite solar cells. The optical and electrical properties of IWO films were found to depend on the oxygen partial pressure of deposition process. Compared with the reference ITO films, the IWO films obtained at an oxygen partial pressure of 0.12 Pa exhibited prominent performance, including higher near-infrared transmittance and carrier mobility. Furthermore, the IWO films showed higher work function than that of the ITO films, resulting in the enhancement of open-circuit voltage (0.982 V vs 0.901 V) and conversion efficiency (12.9 % vs 11.9 %). It can be attributed to that high work function of the IWO films reduced the carrier transport barrier at the interface between transparent electrode and PEDOT:PSS and enhanced the carrier collection near the edge of the perovskite bandgap. The excellent properties of the RPD-prepared IWO films indicate that it is a promising transparent electrode material for p-i-n structured perovskite solar cells, especially for applications requiring low-temperature fabrication.