Optical design of hole transmission nanostructured layers for inverted planar perovskite heterostructure solar cells

A comprehensive optical design of the hole transmission layer for an inverted structure perovskite solar cell was investigated. The optical performance of the perovskite solar cell was studied for different structures, materials and hole transmission layer thicknesses. Organic and inorganic materials were used to implement the hole transmission layer in the form of a single layer and a bi-layer; explicitly, CuSCN, NiO, MoO3, Spiro-MeOTAD, PEDOT:PSS and PTAA. Moreover, the model was set to study a wide range of layer thicknesses (50-600 nm). A computed percentage indicator, which combines the total energy absorption in the perovskite layer and the external quantum efficiency, was used to compare the effectiveness of different hole transmission layers. The maximum indicator value of 40% was recorded for 50 nm NiO single layer, and the bi-layer of NiO and CuSCN; both being 25 nm thick. Also, the hole transmission layer of these two inorganic materials is more efficient for thicknesses up to 200 nm. Alternatively, for greater thicknesses, Spiro-MeOTAD showed better indicator values, as it showed a lower dependency on the layer thickness. The worst hole transmission material is the MoO3, due to its minimum indicator values for all thicknesses.