Infrared Sensitive Solution-processed Quantum Dot Photovoltaics in a Nanoporous Architecture

• Main Author: Klem, Ethan
• Other Authors: Sargent, Edward H.
• Format: Others
• Language: en_ca
• Published: 2008
• Subjects: photovoltaic; quantum dot; infrared; PbS; nanoporous; 0544
• Online Access: http://hdl.handle.net/1807/16748

If solar energy is to be a significant component of our energy supply, technologies are required which produce high efficiency solar cells using inexpensive materials and versatile manufacturing processes. Solution-processed materials have been used to create low cost, easily fabricated devices, but have suffered from low power conversion efficiencies. A lack of infrared energy capture limits their efficiency. In this work we develop solution-processed photovoltaic devices using lead sulphide quantum dots and high surface area porous oxide electrodes. The resultant devices have a spectral response from 400 to 1800 nm. In fabricating these devices we utilize crosslinking molecules. We explore the impact crosslinkers have on the mobility and morphology of quantum dot films using field effect transistors and transmission electron microscopy. We also explore a hybrid organic/inorganic route for controlling the net doping in quantum dot films. We investigate the chemical and compositional changes that lead sulphide quantum dots films undergo during crosslinker treatment and annealing. Using this information we optimize our charge separation efficiency and our open circuit voltage. The resulting devices have an infrared power conversion efficiency of 2%, four orders of magnitude higher than that in previously reported lead sulphide quantum dot devices.