Date of Award
Doctor of Philosophy
Luis A. Echegoyen
Proper collection of charges at the electrodes is an important process in organic solar cells. Interfacial layers between the electrodes and the photoactive layer have been design to improve charge collection and ohmic contacts. The most studied interfacial layer between the anode and the photoactive layer is the negatively charged polymer poly(3,4-ethylendioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), that possesses good hole transporting ability. However, inhomogeneities at the surface of the electrode after deposition of the polymer lower the stability and performance of the OPV devices. Triphenylamine (TPA) derivatives have received increased attention in the organic solar cells (OSCs) field because of their favorable light harvesting properties and good hole transport mobilities, both crucial parameters for obtaining high efficient solar cells. It is well known that after electrochemical oxidation the generated TPA radical cation can undergo a polymerization reaction sequence after consecutive oxidative scans. We have designed and synthesized diverse TPA derivatives to be used as hole transporting materials in both OPVs and hybrid perovskite solar cells. Additionally, self-assembled monolayers (SAMs) have been used as interfacial layers and they have improved ohmic contacts and charge collection. Theoretically, if PEDOT:PSS is substituted with a neutral self-assembled monolayer that can produce a charge-separated state upon exposure to light, device efficiencies should increase with cell polarization. Therefore, donor-fullerene dyads, containing mainly TPA and/or metal porphyrins, were designed and synthesized as potential photo-switched polarizing layers for enhanced efficiencies of solar cell devices.
The synThesis and characterization of functionalized endohedral fullerenes was also studied. Reactions such as asymmetric catalysis using the cation radical of the least reactive endohedral fullerene, Sc3N@Ih-C80, suggests that it is possible to obtain adducts that would not be possible to obtain by any other synthetic method. Application of these functionalized endohedral fullerenes in solar cells is foreseen.
Received from ProQuest
Danisha Marie Rivera Nazario
Rivera Nazario, Danisha Marie, "Triphenylamine-, Porphyrin- And Fullerene-Based Derivatives For Photovoltaic And Other Applications" (2015). Open Access Theses & Dissertations. 938.