One‐step synthesis and deposition of metal oxides: NiO quantum dots as a transport layer for perovskite photovoltaics

One‐step synthesis and deposition of nickel oxide quantum dots using a gas‐phase microplasma process is demonstrated and their applicability as a transport layer for solar cell devices is shown. The process uses a solid nickel metal wire as sacrificial electrode, and the concentration of oxygen gas required in the synthesis is investigated. The quantum dots are characterized for physical, chemical, and optical properties and critical process parameters such as the process throughput are also estimated. Direct one‐step deposition directly on perovskite solar cells is carried out using a computer‐controlled x–y stage and the performance of the solar cell device is assessed.