Effect of Surface Treatment by Chemical-Mechanical Polishing for Transparent Electrode of Perovskite Solar Cells

Abstract

Perovskite solar cells (PSCs) are usually fabricated by using the spin coating method. During the fabrication process, the surface status is very important for energy conversion between layers coated in the substrate. PSCs have multilayer-stacked structures, such as the transparent electrode layer, the perovskite layer, and a metal electrode. The efficiency and uniformity of all layers depend on the surface status of the transparent electrode coated on the glass substrate. Until now, etching methods by chemical processes have been introduced to make the substrate surface smooth and uniform by decreasing surface roughness. However, highly reactive chemical treatments can be harmful to the environment. In this study, we employed an eco-friendly chemical-mechanical polishing (CMP) process to ensure the fluorine-doped tin oxide (FTO) substrate is treated with a smooth surface. Before the perovskite layer and electron transport layer (ETL) are applied, the TiO2 layer is coated with the FTO substrate, and the surface of the FTO substrate is polished using CMP. As a result, the CMP-treated surface of the FTO substrate showed a smooth surface, and the PSCs with CMP treatment did not require conventional TiCl4 treatment.

Preparation of C3N4 Thin Films for Photo-/Electrocatalytic CO2 Reduction to Produce Liquid Hydrocarbons

“…Since the films are very thin, their transmittances are very similar and even better than the transmittance of the bare FTO substrate in some range of wavelength. Since the FTO surface is very rough (R a = 30.78 nm, Figure S1b) and has clear crystal facets, the reflectance of light is serious [24,25]. After deposition of g-C 3 N 4 thin films on FTO surface, the roughness of film become smaller as the Atomic force microscopy (AFM) results shown in Figure 2c,f,i.…”

Polymer-Doped SnO2 as an Electron Transport Layer for Highly Efficient and Stable Perovskite Solar Cells

“…To better understand the surface morphology of the coated films, atomic force microscopy (AFM) was employed. Given that FTO shows a roughness surface of 30 nm [ 66 , 67 ], both SnO 2 ETL films exhibit a smooth surface, as observed in Figure S7a,b . However, a pristine SnO 2 film exhibits a rougher surface than the SnO 2 ETL films (26.32 nm vs. 24.98 nm), which is in line with the surface morphology observed via scanning electron microscopy (SEM), as shown in Figure 2 b,c.…”

Effects of bendable P3CT polymers layer on the photovoltaic performance of perovskite solar cells

“…However, the used TCO thin films are poly-crystalline materials which have atomically non-flat surfaces. The surface roughness of commercial ITO thin films and FTO thin films are about 5 nm [33] and 33 nm [34], respectively, which are more than 5 times of the height of an edge-on P3CT polymer. In other words, the monolayer-like polymers cannot be completely loaded on top of the rough TCO thin films.…”