The Application Of Novel Interfacial Materials And Structure In Organic-inorganic Solar Cells

Along with the mass amount usage of fossil fuels, the issues of environmental pollution and energy shortage have become the main factor that limited the continuing development of our society. More and more countries, corporations and research communities had devoted their effort to develop new energy technology. Among with these candidates, photovoltaic power generation had attracted wide spread attention because of its clean and safety. Although relative high power conversion efficiencies had been achieved by silicon based solar cells, the high soaring costs set back the wide implementation. The new generation solar cells including organic photovoltaics(OPV) and perovskite ones etc. which promised lowing the production costs and increasing the power conversion efficiencies as well, had a bright future.There were two main part works that included in this thesis. Firstly, layered topological insulator-bismuth selenide(Bi2Se3) was prepared and utilized as hole conductor in organic photovoltaics. Detailed investigation was conducted to figure out the improved power conversion efficiencies and device stability. Secondly, TiOx film, embedded with synthesized gold nanoparticles(Au NPs), functioned as electron conductor in perovskite solar cells was studied. We focused on the hot-electron injection that happened at the schottky junction interface and its positive impacts on TiOx film and devices performance. The detailed content was listed below:(1) Layered Bi2Se3 was obtained through the reaction of lithium intercalation and implemented as hole transport layers(HTLs) for inverted organic solar cells. Device based on L-Bi2Se3 obtained a power conversion efficiency(PCE) of 4.37%, which outperformed the ones with evaporated-MoO3 using poly(3-hexylthiophene)(P3HT) as donor material and [6,6]-phenyl-C61-butyric acid methyl ester(PC61BM) as acceptor. In addition, improved device stability was achieved.(2) The large amount of trap states existed in the TiOx film fabricated at low temperature process TiOx film hindered the development of perovskite solar cells. We tried to optimize devices performance via the research on TiOx film thicknesses, processing temperatures and perovskite film morphology. And a PCE of 9.38 % was achieved for perovskite solar cells based on TiOx film with optimized thickness.(3) Double-layer TiOx film embedded with Au NPs that served as electron conductor in perovskite solar cells was utilized to improve the charge transport properties of low temperature(150 oC) processed electron conductive layers through plasmonic-mediated hot carrier injection at metal-semiconductor Schottky junction. The injected electrons helped to fill the trap states in the conduction band of TiOx film, which resulted in higher conductivity Ti Ox film and low work function. And devices based on this sandwiched structure obtained a PCE of 16.2 %.