Re ECF Project: 2012-32

Project Title: Complete biodegradable solar cell on paper substrate: from fabrication setup to device demonstration

Applicant: Dr. CHAN Kwok Leung, Paddy, Department of Mechanical Engineering, The University of Hong Kong

Total Approved Grant: $497,000

Duration: 1/7/2014 to 30/6/2016

Project Status/Remarks: Project completion to be reviewed by the ECF Research Projects Vetting Subcommittee

Scope:
The project aims to-

  • develop the fabrication setup and processing recipe for solar cell on paper substrate; and
  • demonstrate the printed solar cell on paper substrate to the research community, solar cell industry and the public.

Summary of the Findings/Outcomes:
In this project, the project team developed a fabrication recipe to print conductive electrodes onto the paper and plastic substrates by using screen printing and ink-jet printing method. Different from the traditional fabrication method like thermal evaporation or sputtering, the printing method was extremely suitable for organic/inorganic hybrid devices processing. One approach the project team utilized to adjust the surface energy of the substrate was the deposition of parylene layer which could be further optimized with self-assembled monolayer. Having the parylene layer on the paper and plastic substrates, the project team could directly deposited organic semiconductor such as dinaphtho [2,3-b:2’, 3’-f] thieno [3,2-b] thiophene (DNTT) or poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as the p-type layer. Similarly, other n-type material such as fullerene (C60) or n-type silicon could be used onto the substrate to complete the devices. Throughout the project, the optical transparency of the electrode was playing a critical role in the overall performance of the solar cells. The overall hybrid device achieved a power conversion efficiency higher than 6%. For the device biodegradability, 0.2% hydrochloric acid was utilized to dissolve the device and it could be dissolved in a few hours time. The project team achieved organic/inorganic photovoltaic cell with paper substrate.