Steady-State and Transient Response Analysis of DSSC Based on Electron Diffusion Coefficient and Chemical Capacitance

Abstract

A study of the transition from transitory state to steady state in DSSCs based on natural dyes is presented; cochineal was used as dye and Li+, Na+, and K+ were the ions added to the electrolyte. The photocurrent profiles were obtained as a function+ + +of time. Several DSSCs were prepared with different cations and their role and the transitory-to-steady transition was determined. A novel hybrid charge carrier source model based on the Heaviside function H(t) and the Lambert-Beer law, was developed and applied to analysis of the transient response of the output photocurrent. Additionally, the maximum + effective light absorption coefficient α and the electronic extraction rate κ for each ion were determined: (Formula persented) = (0.486, 0.00085, 0.1126) cm-1, and also the electronic extraction rate (Formula persented) = (1410, 19.07, 19.69) cm s-1. The impedance model using Fick’s second law was developed–1–1 for carrier recombination to characterize the photocurrent.