DSSC染料敏化太阳能电池-英文.ppt

Dye Sensitized Nanocrystalline Photovoltaic Cell Group 1 – Luke, Matt, and Jeff Theory Schematic of Graetzel Cell Theory: Charge Separation Charge must be rapidly separated to prevent back reaction. Dye sensitized solar cell, the excited dye transfers an electron to the TiO2 and a hole to the electrolyte. In the PN junction in Si solar cell has a built-in electric field that tears apart the electron-hole pair formed when a photon is absorbed in the junction. Objective Learn about the photovoltaic effect. Understand the Scherrer formula. Procedure: TiO2 Suspension Begin with 6g colloidal Degussa P25 TiO2 Incrementaly add 1mL nitric or acetic acid solution (pH 3-4) nine times, while grinding in mortar and pestle Add the 1mL addition of dilute acid solution only after previous mixing creates a uniform, lump-free paste Process takes about 30min and should be done in ventilated hood Let equilibrate at room temperature for 15 minutes Procedure: Deposition of TiO2 Film Align two conductive glass plates, placing one upside down while the one to be coated is right side up Tape 1 mm wide strip along edges of both plates Tape 4-5 mm strip along top of plate to be coated Uniformly apply TiO2 suspension to edge of plate 5 microliters per square centimeter Distribute TiO2 over plate surface with stirring rod Dry covered plate for 1 minute in covered petri dish Procedure: Deposition of TiO2 Film Anneal TiO2 film on conductive glass Tube furnace at 450 oC 30 minutes Allow conductive glass to cool to room temperature; will take overnight Store plate for later use Procedure: Preparing Anthrocyanin Dye Natural dye obtained from green chlorophyll Red anthocyanin dye Crush 5-6 blackberries, raspberries, etc. in 2 mL deionized H2O and filter (can use paper towel and squeeze filter) Procedure: Staining TiO2 Film Soak TiO2 plate for 10 minutes in anthocyanin dye Insure no white TiO2 can be seen on either side of glass, if it is, soak in dye for five more min Wash film in H2O then ethano