Tuning of Thermoelectric performance of CrSe2 material using dimension engineering

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 ZT_s value of 0.69, while the bulk (p-type) ZT_s 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 ZT_o = 2.18 and the bulk (p-type) has ZT_o = 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.