Properties of Double Electron Transport Layered Perovskite Solar Cells with Different ZrO_2 Layer Thickness

摘要

The photovoltaic properties of TiO_2/ZrO_2 double electron transport layered perovskite solar cells were investigated based on the ZrO_2 layer thickness. Samples were fabricated with a glass/FTO/TiO_2/ZrO_2/ perovskite structure. The TiO_2/ZrO_2 layer thickness ratio was confirmed to be 264/0, 228/168, 228/204, 270/ 242, and 282/288 nm, respectively, using an electron probe microanalyzer. To analyze the photovoltaic characteristics and transmittance of the ZrO_2 layer of the PSCs according to the ZrO_2 layer thickness, a solar simulator, incident photon-to-current conversion efficiency, and ultraviolet-visible-near-infrared spectroscopy were used, respectively. A field emission scanning electron microscopy and atomic force microscopy were used to analyze the microstructure of the ZrO_2 and perovskite layers. As the ZrO_2 layer thickness increased, the energy conversion efficiency (ECE) increased initially, reached a maximum ECE of 14.24% at 204 nm ZrO_2, and then decreased thereafter. The increase in ECE was due to the enhanced electrical conductivity of the ZrO_2, while the decrease was attributed to the reduced transmittance as the thickness of the ZrO_2 increased. In addition, we confirmed that the surface valley spacing in the ZrO_2 layer might affect the grain size and thickness of the perovskite layers, influencing the ECE.