Colloidal Monolayer β-In2Se3Nanosheets with High Photoresponsivity.
We report a low-temperature colloidal synthesis of single-layer, five-atom-thick, β-In2Se3nanosheets with lateral sizes tunable from ∼300 to ∼900 nm, using short aminonitriles (dicyandiamide or cyanamide) as shape controlling agents. The phase and the monolayer nature of the nanosheets were ascertained by analyzing the intensity ratio between two diffraction peaks from two-dimensional slabs of the various phases, determined by diffraction simulations. These findings were further backed-up by comparing and fitting the experimental X-ray diffraction pattern with Debye formula simulated patterns and with side-view high-resolution transmission electron microscopy imaging and simulation. The β-In2Se3nanosheets were found to be indirect band gap semiconductors (Eg= 1.55 eV), and single nanosheet photodetectors demonstrated high photoresponsivity and fast response times.
Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Genova , Via Dodecaneso, 31, 16146, Genova, Italy.
Guilherme
G
Almeida
Sedat
S
Dogan
IMEM-CNR , Parco Area delle Scienze 37/A, I-43124 Parma, Italy.
Giovanni
0000-0001-6424-9102
G
Bertoni
Istituto di Cristallografia, Consiglio Nazionale delle Ricerche , via Amendola 122/O, 70126 Bari, Italy.
Cinzia
C
Giannini
Roberto
R
Gaspari
Center for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia , via Giovanni Pascoli 70/3, I-20133 Milan, Italy.
Stefano
S
Perissinotto
Roman
0000-0003-0066-7019
R
Krahne
Sandeep
S
Ghosh
Liberato
0000-0003-4386-7985
L
Manna