Theflat-band potential (Vfb)and carrier concentration (ND)were calculated from the X-axis intercept and the slope of the linear fit ofthe Mott–Schottky equation i,ii; (A) where e isthe electron charge, ? (= 8.5) is thedielectric constant, ?0 isthe permittivity in vacuum iii.The Mott–Schottky plots (not shown) confirm the n-type behavior of all thefabricated Cd1?xZnxS thin films.
The ND values for all the deposited films were calculatedand are tabulated in Table 2. It can be seen from the Table 2, all the Zn incorporatedsamples shows higher ND andVfb values compared tountreated CdS while sample Z-3 appears to have a higher ND with respect to the other fabricated CdS films alongwith the highest Vfb value(Fig. 1 and Table 2).
The Vfbvalue was found to be tunable with the Zn2+ concentration in thereaction solution. The existence of different Vfb in a same PEC indicates change in relative band edgeposition supports of the fabricated Cd1-xZnxS along withthe Zn2+ concentration. The tunability of the relative band edge position suggests thepossibility of obtaining smooth band lineup throughout the p-n junction 19.These variations in ND and Vfb affect both short circuit current (ISC) and open circuit voltage (VOC) value of the fabricated Cd1-xZnxSphotoelectrodes 1,9,iv. i M. AkifShikhan Aliyev and M.
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