Research

    Dye-sensitized solar cells (DSSCs) have recently emerged as a cost-effective alternative to conventional silicon photovoltaics owing to their high efficiency, simple fabrication process, and low manufacturing cost. In our study, we focus on the preparation of photoanode, such as high quality anatase TiO2 nanoparticles synthesis, electrophoretic deposion method, and screen printing method for high efficiency DSSCs. We also develop CuInS2-QDs/CdS sensitized TiO2 films to enhanced incident light absorption for high efficiency DSSCs.

Result

Electron Transport Patterns in TiO2 Nanotube Arrays Based Dye-Sensitized Solar Cells under Frontside and Backside Illuminations

(1) TiO2 nanotube arrays (NTA), of 17−37 μm in thickness, detached from anodic oxidized Ti foils were used as photo-anodes for dye-sensitized solar cells (DSSCs).

    The Illumination Geometries (Frontside and Backside) and the Corresponding Electron Transport Processes for TiO2 NTA based DSSCs. The crystal defects in the grain boundaries induce trapping/detrapping process and result in a trap-limited diffusion.

Structure and Electron-Conducting Ability of TiO2 Films from Electrophoretic Deposition and Paste-Coating for Dye-Sensitized Solar Cells

(1) An electrophoretic deposition (EPD) method, consisting of repetitive short-term depositions with intermediate drying, was developed to prepare nanocrystalline TiO2 films for dye-sensitized solar cells (DSSCs).

(2) The present study demonstrates that an optimized EPD process can construct a nanocrystalline TiO2 architecture with a minimized void fraction to shorten the electron traveling distance and to effectively collect photogenerated charges, even for films with large thicknesses.

High-performance quantum dot-sensitized solar cells based on sensitization with CuInS2 quantum dots/CdS heterostructure

    The sensitization process involves attaching presynthesized CuInS2 QDs (3.5 nm) to a TiO2 substrate with a bifunctional linker, followed by coating CdS with successive ionic layer adsorption and reaction (SILAR) and ZnS as the last SILAR layer for passivation.

    Schematic illustration of the quantum dot-sensitized solar cell, which consists of a TiO2 nanocrystalline film sensitized with CuInS2-QDs/CdS as the photoanode, a CuS film, deposited on a SnO2:F coated glass (FTO) substrate, as the counter electrode, and a polysulfide electrolyte.A conceptual schematic of the CuInS2-QDs/CdS heterostructure on the TiO2 surface. The inset illustrates the particle-packing network of a CdS film without the CuInS2 QD pillars. Note that coating ZnS to finalize the SILAR deposition is important for passivating the light-absorbing CuInS2-QDs/CdS sensitizers.