Mingwei Shang

Date of Graduation

Spring 2014


Master of Science in Materials Science


Physics, Astronomy and Materials Science

Committee Chair

Lifeng Dong


CuΓééO/ZnO p-n heterojunction, TiOΓéé, dye-sensitized solar cell, electrolyte, electrodes

Subject Categories

Materials Science and Engineering


Solar cells have attracted a lot of interest in recent years with the increasing need for alternative forms of energy. Two types of solar cells are analyzed in this work. First, single-crystal n-type zinc oxide (ZnO) nanorod arrays and p-type cuprous oxide (Cu2O) film were used to fabricate Cu2O/ZnO heterostructures through electrochemical deposition. Electrical measurements and external quantum efficiency were used to characterize the properties of the obtained p-n junction. Second, the effects of different electrolytes and counter electrodes on the cell performance were analyzed in order to improve the photoelectric properties of TiO2-based dye-sensitized solar cells (DSSCs). Iodine-based electrolyte, sulfur-based electrolyte and inorganic solid-state electrolyte CsSnI2.95F0.05 were selected to couple with dye-sensitized TiO2 nanorod arrays. The cell composed of CsSnI2.95F0.05 shows the highest conversion efficiency, around 8.9%. To analyze the effects of counter electrodes on the photovoltaic performance of DSSCs, fluorine doped tin oxide transparent conducting glass (FTO), platinum coated FTO (Pt/FTO), graphite coated FTO (Graphite/FTO), and graphite coated common glass (Graphite/glass) were used as the counter electrodes of the TiO2-based DSSCs with CsSnI2.95F0.05. The cells had power-conversion efficiencies of 2.17%, 9.84%, 7.62%, and 3.45%, respectively. Our findings indicate that due to its unique catalytic and conducting properties, graphite can replace both Pt and FTO as a counter electrode to reduce the fabrication cost of all-solid-state TiO2-based DSSCs.


© Mingwei Shang

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