Approach to Determine the Density-of-States Effective Mass with Carrier Concentration-Dependent Seebeck Coefficient

Band engineering is an effective strategy to improve the electronic transport properties of semiconductors. In thermoelectric materials research, density-of-states effective mass is an undoubted key factor in verifying the band engineering effect and establishing a strategy for enhancing thermoelectric performance. However, estimation of the effective mass is demanding or inaccurate depending on the methods taken. A simple equation is proposed, valid for all degeneracy: Log₁₀ (m_d*T/300) = (2/3) Log₁₀ (n) − (2/3) [20.3 − (0.00508 × |S|) + (1.58 × 0.967^|S|)] that utilizes experimentally determined Seebeck coefficient (S) and carrier concentration (n) to determine the effective mass (m_d*) at a temperature (T). This straightforward equation, which gives an accurate analysis of the band modulation in terms of m_d*, is indispensable in designing thermoelectric materials of maximized performance.