Yong Li

Document Type

Thesis - University Access Only

Award Date

2011

Degree Name

Doctor of Philosophy (PhD)

Department / School

Electrical Engineering and Computer Science

Abstract

Organic-based solar cells including organic solar cells and dye-sensitized solar cells (DSSCs) have drawn considerable attention worldwide as potential competitors to conventional crystalline silicon solar cells and thin film solar cells owing to their prospective advantages to produce large-area, flexible, low-cost, and light-weight devices using simple techniques. However, most energy of the photons from the near infrared (NIR) region to longer wavelengths (~49% of the solar energy) usually cannot be harvested by these devices due to a relatively high band gap of the organic photovoltaic materials. The goal of this work was to develop solution-processable low-band-gap organic photovoltaic materials for low-cost high-efficiency organic-based solar cells. This dissertation depicts in detail the synthesis, characterization, and photovoltaic applications of 17 novel mesoscopic phthalocyanine structures. Three hyperbranched phthalocyanines 1-3 (HBMPc-CN; M = H2, TiO, Cu) were fabricated into cell structures of indium tin nxide/TiO2/TiOx:HBMPc-CN/CuSCN/Au (or carbon) following the extremely-thin absorber concept, showing efficiencies ofup to 0.23%. A series of non-aggregated hyperbranched phthalocyanine dyes 4-8 (HBMPc-COOH; M = H2, AICI, Co, Cu, Zn) were utilized as sensitizers of TiO2 in DSSCs, displaying efficiencies of up to 1.15%. A series of mixed (porphyrinato)(phthalocyaninato) rare-earth double-decker complexes [MmH(TCIPP){Pc(a-OC4H9)8}] (9-15; M = Y, Sm, Eu, Tb, Dy, Ho, Lu; TCIPP = meso-tetrakis( 4-chlorophenyl)porphyrinate; Pc( a-OC4H9 )s =1,4,8,11,15,18,22,25-octakis(l butyloxy)phthalocyaninate) and [Ym(TClPP)(Pc)] (16, Pc= unsubstituted phthalocyaninate), along with a heteroleptic phthalocyaninato yttrium double-decker complex [YmH(Pc){Pc(a-OC4H9)s}] (17), were utilized as broadband absorbers and electron donors, N,N' -bis( 1-ethylhexyl)-3,4:9, 10-perylenebis(dicarbox-imide) or [6,6]-phenyl-C 6 1 butyric acid methyl ester was adopted as primary electron acceptor, and an in situ formed cheap inorganic network of nanoporous TiOx was used as secondary electron acceptor in solution-processed organic-inorganic hybrid solar cells with efficiencies of up to 0.82%. Mesoscopic phthalocyanine structures are low-cost photovoltaic materials with tunable absorption/photophysical properties. Future work should address cell efficiency improvement via material engineering and device engineering to make mesoscopic phthalocyanine materials and solar cells commercially valuable.

Library of Congress Subject Headings

Phthalocyanines

Solar cells

Photovoltaic cells

Format

application/pdf

Number of Pages

250

Publisher

South Dakota State University

Download

Share

COinS