论文标题
带有载体浓度调制的GAN的热电特性：实验和理论研究
Thermoelectric Properties of GaN with Carrier Concentration Modulation: An Experimental and Theoretical Investigation
论文作者
论文摘要
本工作通过将实验工具和计算工具结合在一起研究了N型GAN半导体的较少探索的热电性能。实验在较宽的温度范围内测量了GAN的外延薄膜的塞贝克系数，在77 K至650 K的范围内，台阶的台阶覆盖了低温和高温方案，这是载体浓度的函数2 x1016、2 x1017、2 x 1017、4 x 1017、4 x 1017和8 x 1017 cm-3。发现在室温下测得的塞贝克系数最高，-374 microv/k，最低浓度为4 x 1016 cm -3，单调幅度降低（-327.6 microv/k，-295 microv/k，-295 microv/k，-246 microv/k，-246 microv/k，对于2 x 1017，4 x 1017，4 x 1017，8 x 1017，8 x 1017，8 x 1017，8 x 1017 cm增加。在研究的整个温度范围内，Seebeck系数仍然为负，表明电子是主要的载体。为了了解温度依赖性行为，我们还通过使用Tran-Blaha修改的Becke-Johnson（TB-MBJ）电位进行了电子结构，并分别在Wien2k和Boltztrap代码中实现了传输系数。实验观察到的载体浓度用于计算。在恒定松弛时间近似下获得的估计结果在温度范围为260至625 K的理论和实验数据之间提供了很好的一致性。
The present work investigates the less explored thermoelectric properties of n-type GaN semiconductors by combined both the experimental and computational tools. Seebeck coefficients of epitaxial thin films of GaN were experimentally measured in the wide temperature range from 77 K to 650 K in steps of ~10 K covering both low and high-temperature regimes as a function of carrier concentration 2 x1016, 2 x 1017, 4 x 1017 and 8 x 1017 cm-3. The measured Seebeck coefficient at room temperature was found to be highest, -374 microV/K, at the lowest concentration of 4 x 1016 cm-3 and decreases in magnitude monotonically (-327.6 microV/K, -295 microV/K, -246 microV/K for 2 x 1017, 4 x 1017, 8 x 1017 cm-3, respectively) as the carrier concentration of samples increases. Seebeck coefficient remains negative in the entire temperature range under study indicate that electrons are dominant carriers. To understand the temperature-dependent behavior, we have also carried out the electronic structure, and transport coefficients calculations by using Tran-Blaha modified Becke-Johnson (TB-mBJ) potential, and semiclassical Boltzmann transport theory implemented in WIEN2k and BoltzTraP code, respectively. The experimentally observed carrier concentrations were used in the calculations. The estimated results obtained under constant relaxation time approximations provide a very good agreement between theoretical and experimental data of Seebeck coefficients in the temperature range of 260 to 625 K.
