Few-Layer Nanosheets of n-Type SnSe2.
Layered p-block metal chalcogenides are renowned for thermoelectric energy conversion due to their low thermal conductivity caused by bonding asymmetry and anharmonicity. Recently, single crystalline layered SnSe has created sensation in thermoelectrics due to its ultralow thermal conductivity and high thermoelectric figure of merit. Tin diselenide (SnSe2), an additional layered compound belonging to the Sn-Se phase diagram, possesses a CdI2-type structure. However, synthesis of pure-phase bulk SnSe2by a conventional solid-state route is still remains challenging. A simple solution-based low-temperature synthesis is presented of ultrathin (3-5 nm) few layers (4-6 layers) nanosheets of Cl-doped SnSe2, which possess n-type carrier concentration of 2×1018cm-3with carrier mobility of about 30 cm2V-1s-1at room temperature. SnSe2has a band gap of about 1.6 eV and semiconducting electronic transport in the 300-630 K range. An ultralow thermal conductivity of about 0.67 Wm-1K-1was achieved at room temperature in a hot-pressed dense pellet of Cl-doped SnSe2nanosheets due to the anisotropic layered structure, which gives rise to effective phonon scattering.
New Chemistry Unit (NCU), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur P.O., Bangalore, 560064, India.
Sujoy
S
Saha
New Chemistry Unit (NCU), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur P.O., Bangalore, 560064, India.
Ananya
A
Banik
New Chemistry Unit (NCU), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur P.O., Bangalore, 560064, India. kanishka@jncasr.ac.in.
Kanishka
K
Biswas
layered metal chalcogenides; n-type dopants; nanosheets; thermal conductivity; tin diselenide