The performance of dye-sensitized solar cells (DSCs) fabricated by conventional procedure in humid environment have rapidly declined in outdoor testing. This fact may be caused due to the uptake of water into cells during the process of dye soaking (around 20 - 24 hours) and electrolyte filling under ambient air. In this work a new fabrication procedure, that proved to prevent the water uptake, was established for DSC assembling in high humidity environment. In the procedure, the sandwich cell, assembled from preparative FTO/TiO₂ and FTO/Pt electrodes was filled with N719 (10 mM)/DMF solution for the dye adsorption on TiO₂film in 4 hours. The dye adsorbing, electrolyte filling and cell sealing have been carried out in inert gas atmosphere using a glove box.

By new fabrication procedure the energy conversion efficiency (η) of DSCs was improved on 10%. In addition, DSCs fabricated by new procedure were more stable under outdoor testing, the efficiency was even increased 9% at 14-day-outdoor-exposure. From 30^thday of outdoor test the cell efficiency began slightly decrease, and reached the  initial value after 100-day-exposure.

The effect of co-adsorption with chenodeoxycholic acid (CDA) on DSC performance based on new fabrication procedure was investigated. By addition of 100 mM CDA the short circuit photocurrent has significantly increased, the open circuit voltage slightly increased, and the overall power conversion efficiency of as-prepared DSCs was improved by 8%. However the effect of CDA on cell performance was diminished during outdoor exposure.

The change of DSC characteristics was discussed based on analysis of electrochemical impedance spectroscopy (EIS) data. The enhancement of photocurrent caused by the photo-activation of the cathode interface during first weeks of outdoors exposure, as well was the effect of co-adsorbate, were interpreted from impedance spectra.