A new single-step technique to fabricate transparent hydrophobic surfaces utilizable in perovskite solar cells

We report a simple low-cost novel method for coating an ultrathin hydrophobic film usable for different ap-plications. A hydrophobic layer is fabricated on a TiO2 substrate by hydrolysis of silicone rubber evaporation. The hydrophobic -Si (CH3)3 groups bonded to the substrate by the reaction of hydrophilic ---Si-OH groups with the hydroxyl groups on the TiO2 surface. In addition, the silicone film was introduced in a carbon-based perovskite solar cell as a tunneling passivation layer between the electron transport layer and the active layer to reduce interfacial and extraction losses. An improved perovskite layer with better crystallinity, larger grain size, and higher stability was achieved. The optimal energy conversion efficiency was 17.42% with FF, VOC, and JSC values of 73.76%, 1.1 V, and 21.39 mA cm-2, respectively.

Automated summary

We present a simple and cost-effective method to coat a thin hydrophobic film for various applications. By evaporating silicone rubber and hydrolyzing it on a TiO2 substrate, a hydrophobic layer is formed. The hydrophobic -Si (CH3)3 groups attach to the substrate by reacting with hydrophilic -Si-OH groups on the TiO2 surface. Additionally, the silicone film is utilized as a passivation layer in a perovskite solar cell, improving the perovskite layer's crystallinity, grain size, and stability. The optimized cell exhibits an energy conversion efficiency of 17.42% with FF, VOC, and JSC values of 73.76%, 1.1 V, and 21.39 mA/cm-2, respectively.