Improved performance and stability in quantum dot solar cells through band alignment engineering

Publication Type:

Journal Article


Nat. Mater.,, Volume 13, Issue 8, p.796-801 (2014)






Solution processing is a promising route for the realization of low-cost, large-area, flexible and lightweight photovoltaic devices with short
energy payback time and high specific power. However, solar cells based on
solution-processed organic, inorganic and hybrid materials reported thus
far generally suffer from poor air stability, require an inert-atmosphere
processing environment or necessitate high-temperature processing, all of
which increase manufacturing complexities and costs. Simultaneously
fulfilling the goals of high efficiency, low-temperature fabrication
conditions and good atmospheric stability remains a major technical
challenge, which may be addressed, as we demonstrate here, with the
development of room-temperature solution-processed ZnO/PbS quantum dot
solar cells. By engineering the band alignment of the quantum dot layers
through the use of different ligand treatments, a certified efficiency of
8.55% has been reached. Furthermore, the performance of unencapsulated
devices remains unchanged for over 150 days of storage in air. This
material system introduces a new approach towards the goal of
high-performance air-stable solar cells compatible with simple solution
processes and deposition on flexible substrates.