Tuning of Thermoelectric performance of CrSe2 material using dimension engineering

Abstract

Two-dimensional transition metal dichalcogenides play a crucial role in the development of energy materials. The current theoretical work investigates the structural, electronic, and thermoelectric properties of 2H–CrSe2 material using first-principle calculations and semiclassical Boltzmann transport theory. Dimensional engineering has converted the bulk CrSe2 to a monolayer with hexagonal phase. This conversion has changed the indirect band gap (0.56 eV) of bulk CrSe2 to direct band gap (0.75 eV) of monolayer CrSe2. At room temperature, the monolayer (p-type) has a ZTs value of 0.69, while the bulk (p-type) ZTs value is 0.52. The value of ZT is then varied further using the open circuit concept, yielding a large value due to the low value of thermal conductivity. At 300 K, the monolayer (p-type) has ZTo = 2.18 and the bulk (p-type) has ZTo = 1.08. We obtained the highest value of ZT for p-type monolayer (4.58) compared to p-type bulk (3.17) at 800 K. Our findings revealed the highest ZT values for 2H–CrSe2 monolayer as well as its bulk counterpart.