To introduce a passivation layer, a PEAI salt solution was spin-coated onto the perovskite surface. It is noted that no additional process was carried out for PEAI layer. The device structure of the perovskite solar cells we adopted in this study is shown in Fig. 1a.
This suggests that 3D/2D passivation might be a heretofore unappreciated key to successful polycrystalline thin-film photovoltaics. Finally, the desired attributes of successful low-dimensional layers are presented with rational design strategies for next-generation polycrystalline solar cells.
In recent years, the power conversion efficiency of perovskite solar cells has increased to reach over 20%. Finding an effective means of defect passivation is thought to be a promising route for bringing further increases in the power conversion efficiency and the open-circuit voltage (VOC) of perovskite solar cells.
Surface passivation methods can be categorised into two broad strategies: Reduce the number of interface sites at the surface. Reduce the population of either electrons or holes at the surface. Point one above usually involves the formation of hydrogen and silicon bonds and is commonly referred to as ‘chemical passivation.
In PSCs, several efficient surface passivation methods have been adopted. For example, excess PbI 2 in the perovskite layer, on the surface or at the grain boundary can suppress charge recombination by formation of I-type band alignment 22, 23, 24.
Surface passivation of solar cells is increasingly important as the wafers become thinner since a greater proportion of the overall recombination occurs at the surface regions. The free online resource about photovoltaic manufacturing.