Viñes Francesc, Konstantatos Gerasimos, Illas Francesc
Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, C/Martí i Franquès 1, 08028 Barcelona, Spain.
Phys Chem Chem Phys. 2017 Oct 25;19(41):27940-27944. doi: 10.1039/c7cp05118b.
The influence of cationic disorder on the electronic structure of ternary compounds, here exemplified on AgBiS material, is studied by means of accurate first principles periodic density functional theory based calculations. For AgBiS cationic disorder in going from semiconducting matildite to a metallic arrangement crystal structure is found to induce a significant decrease in the band gap, as a result of cation-disorder conduction band tail states penetrating into the matildite bandgap. Properly aligned conduction band minimum and valence band maximum show that cationic disorders lead to a noticeable drop of the former and a slight increase of the latter. The present results indicate that temperature effects triggering cationic disorder will have a beneficial effect on the photoactivity of AgBiS samples provided that the metallic limit is not reached.
通过基于精确第一性原理的周期性密度泛函理论计算，研究了阳离子无序对三元化合物电子结构的影响，这里以AgBiS材料为例。对于AgBiS，从半导体硫铜铋矿转变为金属排列晶体结构时的阳离子无序，由于阳离子无序导带尾态渗透到硫铜铋矿带隙中，导致带隙显著减小。正确对齐的导带最小值和价带最大值表明，阳离子无序导致前者明显下降，后者略有增加。目前的结果表明，只要未达到金属极限，引发阳离子无序的温度效应将对AgBiS样品的光活性产生有益影响。
