From the peak of the TRMC signal (the maximum photoconductance of the sample), we can estimate the sum of the mobilities of the individual carriers using the equation given below 𝛷𝛷𝛷𝛷𝛷𝛷 = !" !"# # $ $%& % where I0 is the incident intensity per pulse, e is the elementary charge, β is the ratio between the inner broad and narrow dimensions of the waveguide, FA is the fraction of incident photons absorbed within the sample, φ is the charge carrier generation yield, and Σμ is the sum of electron and hole mobilities (Figure ). The effective mobility for both Sb2Se3 and sulfur-treated films was greater than 10 cm 2 V -1 s -1 , which is considerably higher than other water splitting materials such as Fe2O3 (0.005 cm 2 V -1 s -1 ), CuFeO2 (0.2 cm 2 V -1 s -1 ), and BiVO4 (0.08 cm 2 V -1 s -1 ) .