Thin-Film Thermoelectric Generators Comprising Molybdenum-Based MXenes pn Modules

In this study, the thermoelectric characteristics of spin-coated p-Mo₂C and n-Mo₂Ti₂C₃ thin films and the scalability of MXene thin-film thermoelectric generators (TFTEGs) constructed with pn modules are investigated. The in-plane thermal conductivities are measured at room temperature to be 0.37 and 0.45 W (m K)⁻¹ for the p-Mo₂C and n-Mo₂Ti₂C₃ thin films, respectively. The dimensionless figures of merit ZT are determined to be 1.7 × 10⁻⁵ and 2.6 × 10⁻⁴ for the p-Mo₂C and n-Mo₂Ti₂C₃ thin films, respectively. The scalability of the MXene TFTEG is evaluated by the Seebeck voltage being directly proportional to the number of pn modules. The MXene TFTEG constructed with 200-pn modules generates a Seebeck voltage of 399.9 mV and an output power of 6 mW cm⁻² at a ΔT of 5.4 K.