利用新的理論、新計(jì)算工具和強(qiáng)大的計(jì)算能力，電子材料的計(jì)算篩選是實(shí)驗(yàn)探索的一種有效而經(jīng)濟(jì)的選擇。例如這些計(jì)算工具協(xié)助發(fā)現(xiàn)了諸如TmAgTe2、NbFeSb、NbCoSn和CdIn2Te4等許多新的高性能熱電（TE）候選材料。人們還借此類工具探索出高遷移率的氧化物、發(fā)現(xiàn)了作為透明導(dǎo)體的新材料，并可能應(yīng)用于顯示器、發(fā)光二極管和太陽能電池等。一些通過計(jì)算確定的TE候選材料（如Ba2BiTaO6和TaIrGe）已得到實(shí)驗(yàn)驗(yàn)證。許多以前的工作都是基于載流子遷移率μ、電導(dǎo)率σ和塞貝克系數(shù)S的預(yù)測(cè)。盡管基于Boltzmann輸運(yùn)方程（BTE）的最新工具和理論能夠準(zhǔn)確預(yù)測(cè)電子和聲子的輸運(yùn)性質(zhì)，但其高復(fù)雜性和高計(jì)算成本，限制了其高通量篩選預(yù)測(cè)。

該研究提出了一種計(jì)算效率高的第一性原理方法，以預(yù)測(cè)半導(dǎo)體本征電荷輸運(yùn)性質(zhì)。來自新加坡科學(xué)技術(shù)研究局高性能計(jì)算研究所的Gang Wu和Shuo-Wang Yang共同領(lǐng)導(dǎo)的團(tuán)隊(duì)，通過引入廣義Eliashberg函數(shù)并加入光學(xué)聲子極化、雜質(zhì)散射和自由載流子屏蔽等過程，經(jīng)過密度泛函微擾理論的計(jì)算，使該方法在計(jì)算量很小的情況下，尤其對(duì)非極性和極性半導(dǎo)體都能實(shí)現(xiàn)高保真度。該研究論證了極性光學(xué)聲子散射的重要性，這表明在研究極性半導(dǎo)體的電子性質(zhì)時(shí)，在沒有考慮極性光學(xué)聲子散射時(shí)，需格外小心。通過與Si、GaAs、Mg2Si和NbFeSb的實(shí)驗(yàn)和理論結(jié)果進(jìn)行的比較，作者驗(yàn)證了這一方法的可靠性，并揭示了NaInSe2是一種潛在的新型熱電材料。該方法的提出可廣泛應(yīng)用于高遷移率半導(dǎo)體和高性能熱電光伏材料的高通量篩選。

該文近期發(fā)表于npj Computational Materials6:46 (2020)，英文標(biāo)題與摘要如下。

EPIC STAR: a reliable and efficient approach for phonon- and impurity-limited charge transport calculations

Tianqi Deng, Gang Wu, Michael B. Sullivan, Zicong Marvin Wong, Kedar Hippalgaonkar, Jian-Sheng Wang & Shuo-Wang Yang

A computationally efficient first-principles approach to predict intrinsic semiconductor charge transport properties is proposed. By using a generalized Eliashberg function for short-range electron–phonon scattering and analytical expressions for long-range electron–phonon and electron–impurity scattering, fast and reliable prediction of carrier mobility and electronic thermoelectric properties is realized without empirical parameters. This method, which is christened “Energy-dependent Phonon- and Impurity-limited Carrier Scattering Time AppRoximation (EPIC STAR)” approach, is validated by comparing with experimental measurements and other theoretical approaches for several representative semiconductors, from which quantitative agreement for both polar and non-polar, isotropic and anisotropic materials is achieved. The efficiency and robustness of this approach facilitate automated and unsupervised predictions, allowing high-throughput screening and materials discovery of semiconductor materials for conducting, thermoelectric, and other electronic applications.

責(zé)任編輯：xj

原文標(biāo)題：npj: EPIC STAR—限制聲子和雜質(zhì)的電荷輸運(yùn)的計(jì)算

文章出處：【微信公眾號(hào)：知社學(xué)術(shù)圈】歡迎添加關(guān)注！文章轉(zhuǎn)載請(qǐng)注明出處。