Approach to Determine the Density‐of‐States Effective Mass with Carrier Concentration‐Dependent Seebeck Coefficient
Kyu Hyoung Lee, Sang‐il Kim, Jong‐Chan Lim, Jung Young Cho, Heesun Yang, Hyun‐Sik Kim
Abstract
Abstract 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: Log 10 ( m d * T /300) = (2/3) Log 10 ( 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.