Study of spin coating variables for deposition of hole transport nanolayer used in hybrid perovskite solar cells

Abstract

PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly (styrene sulfonate)) is a conductive polymer, which has among its properties a high transmittance to visible light, and has a relatively high electrical conductivity for an organic polymer. This polymer is widely used as one of the key materials in the structure of a perovskite organometallic solar cell (POSC). The main function of PEDOT:PSS is to act as a carrier layer for the positive charges or holes generated by sunlight and direct them to the output electrode of the device. This layer has a thickness of approximately 10 to 50 nanometers. In this research, the spin coating technique is exposed to deposit PEDOT:PSS films with different thicknesses. To achieve this purpose, three variables must be taken into account: the rotation speed, which varies between 1000 and 6000 revolutions per minute. The amount of solution that ranges from 40 to 100 microliters of solution, and the method of deposit on the substrate, which can be with the spin coater off or on when the solution is poured. It was found that depositing the PEDOT:PSS solution with the spin coater turned on at 5000 RPM and 100 microliters of solution yielded nano films that exhibit greater homogeneity and adherence. Leading to the conclusion that this is the best combination for producing uniform and homogeneous hole-transporting films, which should translate into an improved solar cell efficiency.