Photovoltaic Properties and Photocarrier Dynamics of Nanoarchitectural Metal Oxide?Polymer Hybrid Solar Cells

  • 廖 文濱

Student thesis: Doctoral Thesis


In this work we demonstrated metal oxide nanoarchitectures as electron acceptors and transport channels in inverted-type poly(3-hexylthiophene) (P3HT)-based hybrid solar cells Photocarrier dynamics (charge separation recombination and transport properties) of hybrid solar cells are investigated and characterized by time-resolved photoluminescence (TRPL) impedance spectroscopy (IS) and intensity-modulated photocurrent spectroscopy (IMPS) measurements In the first part we demonstrated ordered hybrid polymer solar cells fabricated by using rutile TiO2 nanoarchitecture (nanorod (NR) and nanodendrite (ND)) arrays and P3HT Interfacial modification with dye molecules in this work can significantly improve the cell performance of ordered TiO2 nanorod (NR)–P3HT hybrid solar cells Equilibrium energy band diagrams of dye-modified TiO2 NR?P3HT hybrid solar cells are established by integrating cyclic voltammetry (CV) and Kelvin probe force microscope (KPM) measurements The dye molecules Z907 and D149 in the hybrid solar cells not only provide an appropriate band alignment between TiO2/P3HT interfaces but also improve the chemical compatibility of interface morphology of the hybrids Besides three-dimensional TiO2 nanodendrite (ND) arrays are employed to further increase the interfacial area in hybrid solar cells A power conversion efficiency (PCE) of 3 12% is achieved in the D149-modified TiO2 ND array/P3HT hybrid solar cell Second we demonstrated a nanoarchitectural hybrid solar cell integrating an ordered TiO2 NR array and a bulk heterojunction (BHJ) of ZnO nanoparticle (NP)/P3HT into cells The cell was fabricated by infiltrating a solution containing diethylzinc (DEZ) and P3HT into the interstices of TiO2 NRs An inorganic network composed of tiny ZnO nanocrystals is in situ generated in the active layer within the interstices of TiO2 NRs The TiO2 NR arrays in hybrid solar cell not only serve as an electron transporter/collector extended from the FTO electrode to sustain the efficient electron collection but also serve as a scaffold to hold the sufficient amount of ZnO/P3HT hybrid The in-situ-generated ZnO NP/P3HT hybrid with superior charge separation efficiency can be thickened in the presence of a TiO2 NR array for increasing the light-harvesting efficiency An efficiency of 2 46% is therefore attained in the TiO2 NR?ZnO/P3HT hybrid solar cell without interfacial modification At last we incorporated a gold?silica core?shell (Au@silica) nanoparticle (NP) into the metal oxide nanoarchitecture/P3HT hybrid Finite difference time domain (FDTD) simulation shows the existence of an asymmetric quadrupole of Fano resonance on the Au@silica-NP surface The charge separation enhancement in the Au@silica-NP-incorporated hybrid contributed to the Fano resonance induced electric field is directly evidenced by TRPL measurements with an additional green light illumination The increase of the degree of P3HT order in the hybrid by adding Au@silica NPs into the hybrid active layer may also enhance current density in the cell Compared to the metal oxide nanoarchitecture/P3HT hybrid solar cell a 30% enhancement of short-circuit current density (Jsc) is attained in the P3HT-based nanoarchitectural Fano solar cell (NAFSC) with Au@silica NPs
Date of Award2015 Jul 27
Original languageEnglish
SupervisorJih-Jen Wu (Supervisor)

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