IntroductionDye-sensitized solar cells (DSSC), as the third generation of solar cells, have the advantages of low cost, environmental protection, pollution-free, and abundant raw materials. Conventional liquid-state electrolyte of DSSC restricts an absorption capacity of visible light and is corrosive, which is considered as an obstacle to the long-term use of DSSC. Solid-state electrolyte has attracted much attention because it overcomes the shortcomings of liquid-state electrolyte (i.e., volatile organic solvent, poor stability and easy leakage). TiO₂ is often used as a photoanode material for DSSC, and its conduction band can match the energy level of common dyes to accelerate electron transfer. However. TiO₂ has a low electron mobility, a low conductivity, a long-term ultraviolet irradiation and the existence of oxygen vacancy, which hinders the effective current output and reduces the photoelectric conversion efficiency. ZnO material can replace TiO₂ as a photoanode because of its high electron mobility and transparency, and it is also a wide-band gap semiconductor material. To improve the photoelectric conversion efficiency of DSSC and solve the problem of liquid-state electrolyte leakage, ZnO solid-state dye-sensitized solar cells were simulated by a software named SCAPS-1D, and the photoelectric performance of solid-state DSCC was analyzed.MethodsBased on FTO/ZnO/N719 / PEDOT: PSS/Au structure modeling by the software SCAPS-1D, a solid-state DSSC model in each layer material interface lose band gap, dielectric constant, mobility and other parameters, and inside layer and layer between the defects was set up under AM1.5G 1 standard solar lighting at an incident light power of 100 mW/cm². The material defect was set as a neutral defect to ensure that the defect could generate SRH recombination without generating space charge because the charge recombination mode of DSSC was mainly SRH. The Poisson equation, carrier continuity equation and carrier drift diffusion equation were numerically solved by the software of SCAPS-1D. The influences of material thickness, operating temperature, series parallel resistance and back contact metal type on the DSSC photoelectric parameters were simulated, and the internal mechanism of the influences of various factors on the DSSC was analyzed.Results and discussionThe open circuit voltage, short circuit current density and photoelectric conversion efficiency increase significantly, and the thickness continues to increase to 1000 nm, as well as the photoelectric parameters increase slowly when the thickness of the dye layer increases from 100 nm to 500 nm. The maximum photoelectric conversion efficiency can be obtained at the thickness of electron transport layer of 20 nm. The photoelectric conversion efficiency increases with the increase of hole transport layer thickness. The efficiency decreases with the increase of operating temperature, and the maximum photoelectric conversion efficiency is 15.17% at 300 K. The open circuit voltage and short circuit current density change little, and the filling factor and photoelectric conversion efficiency decrease when DSSC series resistance increases. The short circuit current density basically unchanges, and other parameters improve when the shunt resistance increases. The effect of changing the type of back contact metal on the photoelectric performance of DSSC is analyzed. The open circuit voltage, short circuit current density and photoelectric conversion efficiency all increase when the back contact metal work function value increases, and the maximum photoelectric conversion efficiency can be obtained when Au is used as the back contact metal.ConclusionsThe optimal thickness of dye layer was 500 nm, and the maximum photoelectric conversion efficiency could be obtained at the thickness of electron transport layer of 20 nm, and the photoelectric conversion efficiency increased with the thickness of hole transport layer. The maximum photoelectric conversion efficiency was 15.17% at the operating temperature of 300 K. The series parallel resistance had an important effect on the photoelectric performance of DSSC. The smaller the series resistance was, the larger the parallel resistance could be, for the improvement of the photoelectric conversion efficiency of DSSC. The electrical conversion efficiency increased when the back contact metal work function value increased, and the maximum photoelectric conversion efficiency could be obtained as Au was used as the back contact metal.