TY - JOUR
T1 - Photogeneration and Mobility of Charge Carriers in Atomically Thin Colloidal InSe Nanosheets Probed by Ultrafast Terahertz Spectroscopy
AU - Lauth, Jannika
AU - Kulkarni, Aditya
AU - Spoor, Frank C M
AU - Renaud, Nicolas
AU - Grozema, Ferdinand C.
AU - Houtepen, Arjan J.
AU - Schins, Juleon M.
AU - Kinge, Sachin
AU - Siebbeles, Laurens D A
N1 - Accepted Author Manuscript
PY - 2016/10/20
Y1 - 2016/10/20
N2 - The implementation of next generation ultrathin electronics by applying highly promising dimensionality-dependent physical properties of two-dimensional (2D) semiconductors is ever increasing. In this context, the van der Waals layered semiconductor InSe has proven its potential as photodetecting material with high charge carrier mobility. We have determined the photogeneration charge carrier quantum yield and mobility in atomically thin colloidal InSe nanosheets (inorganic layer thickness 0.8-1.7 nm, mono/double-layers, ≤ 5 nm including ligands) by ultrafast transient terahertz (THz) spectroscopy. A near unity quantum yield of free charge carriers is determined for low photoexcitation density. The charge carrier quantum yield decreases at higher excitation density due to recombination of electrons and holes, leading to the formation of neutral excitons. In the THz frequency domain, we probe a charge mobility as high as 20 ± 2 cm2/(V s). The THz mobility is similar to field-effect transistor mobilities extracted from unmodified exfoliated thin InSe devices. The current work provides the first results on charge carrier dynamics in ultrathin colloidal InSe nanosheets.
AB - The implementation of next generation ultrathin electronics by applying highly promising dimensionality-dependent physical properties of two-dimensional (2D) semiconductors is ever increasing. In this context, the van der Waals layered semiconductor InSe has proven its potential as photodetecting material with high charge carrier mobility. We have determined the photogeneration charge carrier quantum yield and mobility in atomically thin colloidal InSe nanosheets (inorganic layer thickness 0.8-1.7 nm, mono/double-layers, ≤ 5 nm including ligands) by ultrafast transient terahertz (THz) spectroscopy. A near unity quantum yield of free charge carriers is determined for low photoexcitation density. The charge carrier quantum yield decreases at higher excitation density due to recombination of electrons and holes, leading to the formation of neutral excitons. In the THz frequency domain, we probe a charge mobility as high as 20 ± 2 cm2/(V s). The THz mobility is similar to field-effect transistor mobilities extracted from unmodified exfoliated thin InSe devices. The current work provides the first results on charge carrier dynamics in ultrathin colloidal InSe nanosheets.
UR - http://www.scopus.com/inward/record.url?scp=84992212989&partnerID=8YFLogxK
U2 - 10.1021/acs.jpclett.6b01835
DO - 10.1021/acs.jpclett.6b01835
M3 - Article
AN - SCOPUS:84992212989
SN - 1948-7185
VL - 7
SP - 4191
EP - 4196
JO - The Journal of Physical Chemistry Letters
JF - The Journal of Physical Chemistry Letters
IS - 20
ER -