HZDR’s SRF Gun-II is an excellent demonstration of SRF technology application in the field of electron sources operating in continuous wave mode. As well known, quality of the photocathode is crucial for op-erational stability and reliability of an SRF gun. In this contribution, various studies on Cs2Te cathodes, in-cluding cleaning, preparation, transport/insertion, RF and beam operation will be summariesed. We will look back at the achievements and open issues, and discuss possible improvements and further development.