I have tried performing electrochemical impedance measurements on quantum dot solar cells (2 electrode device). However, each time I see some bubbling from the electrolyte which eventually rips off the TiO2 film and the counter electrode from the conducting substrate. I have tried using different electrolytes viz. polysulfide in water and polysulfide in water+methanol mixture (1:1). The measurement parameters that I use are : bias voltage (0 to 0.5 or 0 to -0.5 V), AC signal amplitude (10mV), frequency (1 MHz to 0.1 Hz). Measurements are done under dark conditions. Also, when I measure with the 3 electrode set-up under otherwise identical conditions, I face no issues like electrolyte bubbling. How can I get around this ?