Dye-sensitized cells (DSCs) have attracted worldwide attention because of their simple fabrication process and lower requirement of high-purity materials compared with silicon-based solar cells. The general structure of a DSC comprises a mesoporous titanium oxide (TiO2) film that absorbs a monolayer of sensitizers as the photoanode, an electrolyte system containing an iodide/triiodide (I–/I3 –) redox couple in a proper medium and functional additives, and a catalytic counter electrode (CE).
Our interest in DSC includes:
1. Efficient counter electrode material and process:
Counter electrode is responsible for collecting electrons from external circuits by reducing I3 – with minimum energy loss. We have developed a unique “two step coating” process to immobilize platinum nano-clusters, graphene nano-platelets…etc onto conducting glass substrate as the counter electrode for DSC.
2. Treatment, modification and optimization on various interfaces in a DSC:
Creating a unidirectional electron transport is one of the key factors of reaching high power energy conversion efficiency in DSC. Unfortunately, undesired electron pathway called recombination causes photocurrent loss. Herein we focus on retarding the recombination occurring at FTO/electrolyte interface by using Nb2O5 blocking layer owing to slightly higher conduction band position than TiO2.
3. Scale-up Engineering and application evaluation:
4. DSC in dim light system:
Under dim light conditions, DSCs have a very high response at visible light range. Therefore, DSCs are aimed towards indoor environment. We developed a movable trolley with spectral irradiance meter as a scheme to control illumination.