چكيده به لاتين
Chalcogenides are one of the absorber layers of thin film solar cells. These materials are a combination of the elements copper, indium, gallium and selenium, and their band gap is in the optimal range for single solar cells. In this thesis, new structures have been designed and analyzed to improve the photovoltaic parameters of chalcogenide solar cells. The proposed structures are designed to simultaneously improve efficiency, open circuit voltage, and short-circuit current density. The use of CdS replacement buffer layers, the addition of CIGS and SnSe thin Intermediate layer between the absorber layer/back contact, the use of double absorber layers and the band gap grading of the absorber layer are among the proposed structures that are analyzed. The simulations showed that ZnS, SnS2, ZTO, In2S3 can be used as a buffer layer to achieve a efficiency above 23%. By adding CIGS and SnSe thin intermediate layer, between the absorber layer/back contact resulted in a significant reduction in recombination losses (less than 25 mA/cm2). Using the above layers and after improving the structure as a p+pn junction, effiency of 27.37%, 27.88% and 28.24% were obtained, respectively. Also, the reduction of recombination of minority carriers in the back contact in the proposed structures led to an increase in open circuit voltage equivalent to 807mV,835 mV and 887mV, respectively. Then, with the help of band gap grading of the absorber layer, which increases the photon absorption, the efficiency was 38.86%.
