Strong Photocurrent from Two-Dimensional Excitons in Solution-Processed Stacked Perovskite Semiconductor Sheets.
Room-temperature photocurrent measurements in two-dimensional (2D) inorganic-organic perovskite devices reveal that excitons strongly contribute to the photocurrents despite possessing binding energies over 10 times larger than the thermal energies. The p-type (C6H9C2H4NH3)2PbI4 liberates photocarriers at metallic Schottky aluminum contacts, but incorporating electron- and hole-transport layers enhances the extracted photocurrents by 100-fold. A further 10-fold gain is found when TiO2 nanoparticles are directly integrated into the perovskite layers, although the 2D exciton semiconducting layers are not significantly disrupted. These results show that strong excitonic materials may be useful as photovoltaic materials despite high exciton binding energies and suggest mechanisms to better understand the photovoltaic properties of the related three-dimensional perovskites.
Nanophotonics Laboratory, Department of Physics, Indian Institute of Technology Delhi , New Delhi 110 016, India.
Shahab
S
Ahmad
Nanophotonics Laboratory, Department of Physics, Indian Institute of Technology Delhi , New Delhi 110 016, India.
Pawan K
PK
Kanaujia
Harry J
HJ
Beeson
Antonio
A
Abate
Felix
F
Deschler
Dan
D
Credgington
Adolphe Merkle Institute, University of Fribourg , Chemin des Verdiers 4, CH-1700 Fribourg, Switzerland.
Ullrich
U
Steiner
Nanophotonics Laboratory, Department of Physics, Indian Institute of Technology Delhi , New Delhi 110 016, India.
G Vijaya
GV
Prakash
Jeremy J
JJ
Baumberg
exciton photocurrent; inorganic−organic hybrid; layered perovskite; photodetector; room-temperature exciton