Deposition of zinc oxide as an electron transport layer in planar perovskite solar cells by spray and SILAR methods comparable with spin coating.

CHNHPbI planar-structure perovskite solar cells were fabricated with the configuration FTO/ZnO/CHNHPbI/Au. ZnO nanoparticles were synthesized by the precipitation method. Three different deposition methods including spin-coating, spraying and successive ionic layer adsorption and reaction (SILAR) were applied to fabricate the ZnO films as electron transport layers. Certain analyses, such as XRD, SEM, FESEM, UV-visible and - measurements, were carried out to evaluate the performance of the cells. The best cell performance was achieved for the perovskite solar cell with a ZnO film coated by the spin method. The average efficiency was 7% without using any hole transport materials and 10.25% using spiro-OMeTAD as a hole transport material. The average efficiencies of the cells coated by the spraying and SILAR methods using spiro-OMeTAD, were found to be 8.64% and 7.7% respectively. This study demonstrates the versatility of the spray and SILAR coating methods and their potential for fabricating low-cost, large scale, flexible and mass produced perovskite solar cells.