title: Cauliflower-like SnO2 hollow microspheres as anode and carbon fiber as cathode for high performance quantum dot and dye-sensitized solar cells.
abstract: Cauliflower-like tin oxide (SnO2) hollow microspheres (HMS) sensitized with multilayer quantum dots (QDs) as photoanode and alternative stable, low-cost counter electrode are employed for the first time in QD-sensitized solar cells (QDSCs). Cauliflower-like SnO2 hollow spheres mainly consist of 50 nm-sized agglomerated nanoparticles; they possess a high internal surface area and light scattering in between the microspheres and shell layers. This makes them promising photoanode material for both QDSCs and dye-sensitized solar cells (DSCs). Successive ionic layer adsorption and reaction (SILAR) method and chemical bath deposition (CBD) are used for QD-sensitizing the SnO2 microspheres. Additionally, carbon-nanofiber (CNF) with a unique structure is used as an alternative counter electrode (CE) and compared with the standard platinum (Pt) CE. Their electrocatalytic properties are measured using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and Tafel-polarization. Under 1 sun illumination, solar cells made with hollow SnO2 photoanode sandwiched with the stable CNF CE showed a power conversion efficiency of 2.5% in QDSCs and 3.0% for DSCs, which is quite promising with the standard Pt CE (QDSCs: 2.1%, and DSCs: 3.6%).
authors: Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Korea. srhee@postech.ac.kr.
authors: Veerappan
authors: V
authors: Ganapathy
authors: Eui-Hyun
authors: EH
authors: Kong
authors: Yoon-Cheol
authors: YC
authors: Park
authors: Hyun Myung
authors: HM
authors: Jang
authors: Shi-Woo
authors: SW
authors: Rhee
mesh_terms: D002244:Carbon / Q000737:chemistry*; D000077482:Carbon Fiber; D004396:Coloring Agents / Q000737:chemistry*; D055664:Electrochemical Techniques; D004566:Electrodes; D008863:Microspheres; D057139:Nanofibers / Q000737:chemistry; D045663:Quantum Dots / Q000737:chemistry*; D012993:Solar Energy; D017971:Tin Compounds / Q000737:chemistry*
chemical_list: D000077482:Carbon Fiber; D004396:Coloring Agents; D017971:Tin Compounds; D002244:Carbon; C045358:stannic oxide