Abstract:
We developed and tested an approach for predicting trends for efficient hot carrier generation among disordered metal alloys. We provide a simple argument for the importance of indirect transitions in the presence of disorder, thus justifying the use of joint density of states (JDOS)-like quantities for exploring these trends. We introduce a newJDOS-like quantity,JDOSK, which heuristically accounts for longer lifetimes of quasiparticles close to the Fermi energy. To demonstrate the efficacy of this new quantity, we apply it to the study of Cu50X50where X = Ag, Au, Pd and Y50Pd50where Y = Au, Ni. We predict that Ni50Pd50produces the most hot carriers among the alloys considered. The improvement in the density of excited photocarriers over the base alloy used, Cu50Ag50, is 3.4 times for 800 nm and 19 times for 1550 nm light. This boost in hot-carrier generation is consequence of the ferromagnetic nature of the Ni alloy. We argue that our method allows efficient material-specific predictions for low bias photoconductivity of alloys.
摘要:
我们已经开发了一种方法来预测无序金属合金中有效热载流子生成的趋势。我们提供了一个简单的论据,说明在存在无序的情况下间接过渡的重要性,从而证明使用联合国家密度(JDOS)类量来探索这些趋势是合理的。我们引入了一个新的类似JDOS的数量,JDOSK,它启发式地结合了粒子寿命的差异,这取决于它们的激发能量。为了证明这个新数量的有效性,我们将其应用于Cu50X50的研究,其中X=Ag,Au,Pd和Y50Pd50,其中Y=Au,Ni.我们预测Ni50Pd50在所考虑的合金中产生最多的热载流子。与所用的基础合金相比,激发光载流子的密度有所提高,Cu50Ag50,对于800nm是3.4倍,对于1550nm是19倍。热载流子产生的这种增加是Ni合金的铁磁性质的结果。我们认为,我们的方法可以对合金的低偏置光电导进行有效的材料特定预测。