论文标题
强力电子偶联和载体自我诱捕SB $ _2 $ S $ _3 $
Strong electron-phonon coupling and carrier self-trapping in Sb$_2$S$_3$
论文作者
论文摘要
胰岛硫化物（SB $ _2 $ S $ _3 $）是一种土壤丰富且无毒的材料，正在研究太阳能转换应用。但是，它仍然遭受功率转换效率较差的损失，并且通常归因于点或界面缺陷和陷阱状态的大型开路电压损耗。最近，已经提出了一个自困的激子作为性能损失的微观起源。 By using first-principles methods, we demonstrate that Sb$_2$S$_3$ exhibits strong electron-phonon coupling, which results in a large renormalization of 200 meV of the absorption edge when temperature increases from 10K to 300K, and in a quasi-1D electron polaron that is delocalized in the ribbon direction of the crystal structure, but localized in the inter-ribbon directions. 67 MEV的计算出的极性形成能与实验测量非常吻合，这表明自被困的激子可能随着电子极化子的介导而形成。我们的结果表明，在光电量应用中，系统研究电子 - 音波耦合和极化子形成的重要性。
Antimony sulphide (Sb$_2$S$_3$) is an Earth-abundant and non-toxic material that is under investigation for solar energy conversion applications. However, it still suffers from poor power conversion efficiency and a large open circuit voltage loss that have usually been attributed to point or interfacial defects and trap states. More recently, a self-trapped exciton has been suggested as the microscopic origin for the performance loss. By using first-principles methods, we demonstrate that Sb$_2$S$_3$ exhibits strong electron-phonon coupling, which results in a large renormalization of 200 meV of the absorption edge when temperature increases from 10K to 300K, and in a quasi-1D electron polaron that is delocalized in the ribbon direction of the crystal structure, but localized in the inter-ribbon directions. The calculated polaron formation energy of 67 meV agrees well with experimental measurements, suggesting that self-trapped excitons are likely to form with the mediation of an electron polaron. Our results demonstrate the importance of systematically investigating electron-phonon coupling and polaron formation in the antimony chalcogenide family of semiconductors for optoelectronic applications.
