Colloidal PbS quantum dot solar cells with high fill factor.
We fabricate PbS colloidal quantum dot (QD)-based solar cells using a fullerene derivative as the electron-transporting layer (ETL). A thiol treatment and oxidation process are used to modify the morphology and electronic structure of the QD films, resulting in devices that exhibit a fill factor (FF) as high as 62%. We also show that, for QDs with a band gap of less than 1 eV, an open-circuit voltage (VOC) of 0.47 V can be achieved. The power conversion efficiency reaches 1.3% under 1 sun AM1.5 test conditions and 2.4% under monochromatic infrared (lambda=1310 nm) illumination. A consistent mechanism for device operation is developed through a circuit model and experimental measurements, shedding light on new approaches for optimization of solar cell performance by modifying the interface between the QDs and the neighboring charge transport layers.
Zhao
Ni
N
Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Osedach
Tim P
TP
Chang
Liang-Yi
LY
Geyer
Scott M
SM
Wanger
Darcy
D
Binda
Maddalena T
MT
Arango
Alexi C
AC
Bawendi
Moungi G
MG
Bulovic
Vladimir
V