I guess it really depends on your budget. The Keithley SMU is a great piece of kit. During my PhD I conducted the majority of my electrochemical measurements with SMUs (specifically Agilent's B1550A semiconductor analyser and some older Keithley SMUs) without any issues.
Keithley have started to provide guides on using their SMUs for electrochemical measurements. In fact; they offer the 2450-EC model:
However, the Autloab potentiostat will come with software tailored for performing a range of electrochemical measurements and to perform analysis. Furthermore, you'll also have access to their customer support.
Thank you for adding very much helpful information.
I still have the question that is it worth buying Autolab potentiostat presently for IV measurements of a solar cells. and for later we can have the attachments of EIS.
Suhail Anjum Abdur Raheem Sayyed What equipment did you choose? I´m looking for the same as you. I´m thinking in https://www.tek.com/keithley-source-measure-units/smu-2450-60-graphical-sourcemeter-manual-12, I want