Efficient All-Evaporated pin-Perovskite Solar Cells: A Promising Approach Toward Industrial Large-Scale Fabrication

Vacuum-based deposition techniques are a common route for the fabrication of high-quality optoelectronic devices on an industrialized scale at low cost and high yield. In the field of perovskite-based photovoltaics, however, vacuum deposition methods are less researched in the community today. Even though the fundamental concept of thermal evaporation of perovskite-based solar cells has been demonstrated, the number of reports about efficient upscalable all-evaporated approaches employing inexpensive raw materials is still limited. In this contribution, a novel architecture for efficient all-evaporated perovskite solar cells in pin -architecture based on a co-evaporated CH3NH3PbI3 absorber deposited on top of an electron-beam evaporated NiOx hole transport layer is reported. Stabilized power conversion efficiencies as high as 16.1% are achieved, resulting in the most efficient thermally evaporated perovskite solar cells employing a pin -architecture. Moreover, it is the first time in the literature that a co-evaporated perovskite absorber deposited directly on top of a metal oxide exceeeds a stable power conversion efficiency above 15%. Next to efficient devices, a remarkable stability against temperature variations up to 80 °C is demonstrated, highlighting the promising thermal stability of the employed charge extracting layers. Replacing the expensive gold rear electrode by copper reduces the material costs of the approach significantly while maintaining a good device performance and stability. The homogeneity and ease of upscaling of the all-evaporated approach toward industrial relevant areas is demonstrated by light-beam induced current mapping. Finally, a homogeneous deposition of the functional layers of the approach on top of a textured silicon wafer is shown.