The effects of doped buffer layers on efficiency of organic solar cells and encapsulation of these solar cells by chemical vapor deposition technique

In the first part of this thesis work, it has been work on electron transport layer with base on P3HT:PCBM polymer solar cell. First, ZnO synthesized by sol-gel method was optimized and the highest efficiency was achieved by synthesis at 0.1 M concentration, coating at 2000 rpm and annealing at 150 ° C. Later, devices were made with different ZnO synthesis methods (sol-gel, nanocrystal, solution process) and the advantages and disadvantages of these methods were compared. After determined the sol-gel method was the most suitable method, Au np's synthesized by slightly modified Turkevich method, were added to ZnO at different percentages by volume. The best efficiency result (3.48%) was achieved with the device using 10% Au/ZnO. In the second part of the thesis, cells were encapsulated using initiator chemical vapor deposition (iCVD) method and stability tests were carried out. Unencapsulated devices were kept in under room conditions, desiccator, and glovebox to clearly see the negative effects of O2 and moisture on the devices in the stability experiments. In addition, the encapsulated devices were kept under room conditions. In this context, the devices were encapsulated at 100, 200 and 300 nm thicknesses with PHFBA polymer in the batch iCVD system and measurements were taken once a week for eight weeks. At the end of eight weeks, without encapsulation devices were kept under room conditions, desiccator and glovebox, lost approximately 90%, 60% and 20% efficiency, respectively. On the other hand, this value was found to be approximately 30% for the devices that were encapsulated.