All vapor-deposited lead-free doped CsSnBr3 planar solar cells

We demonstrate all thermal vapor-deposited CsSnBr3 perovskite solar cells. The cell architecture consists of a planar CsSnBr3 heterojunction where the perovskite layer is grown by thin sequential deposition of SnBr2 and CsBr allowing for immediate reaction. While other halides of CsSnX3 (e.g. X=Cl, I) are extremely air sensitive and change color within seconds, illumination tests performed on unencapsulated CsSnBr3 devices in ambient air show no change over the span of hours. Further, we evaluate the impact of low-temperature annealing and incorporation of various fluoride passivating dopant profiles via vapor deposition. Our results demonstrate an exciting alternative pathway to develop all-inorganic lead-free perovskite photovoltaics.