CHOWDHURY, MD. INZAMAM UL ALAMHOSSAIN, MD. MOHSIN2023-06-172023-06-172021-09http://dspace.iiuc.ac.bd:8080/xmlui/handle/123456789/6621submitted by Md. Inzamam Ul Alam Chowdhury, bearing Matric ID. ET 163005 and Md. Mohsin Hossain, bearing Matric ID. ET 163007 of session Autumn 2020In this investigation the effect of varying compression temperature on photovoltaic performance for TiO2 based dye-sensitized-solar-cell (DSSC) has been observed using electrochemical impedance spectroscopy (EIS) analysis. The cells are fabricated using a new electrophoretic deposition technique that is four-layer-four-side electrophoretic deposition which ensures homogenous crack free photo electrode surface. Electrodeposited photo anodes are compressed at varying compression temperature (room temperature to 90 ℃) as an post deposition treatment. From the impedance spectroscopy analysis the changes of impedance in Nyquist plot (Z′ vs. Z′′) shows that due to changes in compression temperature (room temperature to 90 ℃) the values of charge transfer resistance Rct(AE) are reduced and that's why more electrons are conducted inside the film. Shifting of characteristics frequency peak (Fmax) towards low frequency increases the electron life time (𝜏) which has been observed by increasing the compression temperature up to 70 ℃. Since open circuit voltage (Voc) is proportional to electron life time, with the increasing of electron life time will have higher open circuit voltage (Voc ) value by increasing the compression temperature up to 70 ℃. The Fill Factor (FF) has been improved due to the uniformity of layers by varying the compression temperature up to 70 ℃ . Because of the significant improvement of open circuit voltage (Voc ) , photo current density (Jsc,) and Fill Factor (FF) the overall efficiency (η) has also substantially improved by the insertion of compressed temperature up to 70 ℃ . The series resistance of the cell (calculated from EIS data) reduces by increasing up to 70 ℃ compressed heat. Similar results have been observed from the calculated series resistance from the I-V curve which is the reason for change in the photovoltaic performance. On the other hand the shunt resistance of the cell (calculated from EIS data) increases with the increasing compression temperature up to 70 ℃ . Thus same results have been observed from the calculated shunt resistance from the I-V curve which makes an impact for the change in the photovoltaic performance. So photovoltaic performance and parameters from impedance spectroscopy analysis and from I-V curve matches with each other. At optimum 70 ℃ compression temperature and 40MPa compression pressure the maximum efficiency (η) of 3.85% has been attained which gives the open circuit voltage (Voc ), photo current density (Jsc ) and fill factor of 0.739 V, 9.30 mA/cm2 and 0.58 respectively.Thesis