Lunca-Popa P, Afonso J, Grysan P, Crêpellière J, Leturcq R, Lenoble D
Materials Research and Technology Department (MRT), Luxembourg Institute of Science and Technology (LIST), 41 rue de Brill, L-4422, Belvaux, Luxembourg.
Sci Rep. 2018 May 8;8(1):7216. doi: 10.1038/s41598-018-25659-3.
Off-stoichiometric copper chromium oxide delafossite received lately a great interest due to its high p-type electrical conductivity and adequate optical transmittance in the visible range. However, for a suitable integration in active devices such as p-n junctions, transistors or optoelectronic devices, the electronic properties must be efficiently tailored. Here, post-deposition thermal treatment is proven as an adequate approach for finely controlling the electrical properties of this former degenerate semiconducting material. The energetics of the annealing process are investigated using two different approaches, as a function of the annealing temperature and as a function of the annealing time, allowing the accurate determination of the activation energy of the annealing of defects. By using this method, the electrical carrier concentration was varied in the 10 - 10 cm range while the recorded changes in the drift mobility covered three orders of magnitude. Moreover, we demonstrate the ability to accurately manipulate the Fermi level of such materials, which is of great importance in controlling the carrier injection and extraction in optoelectronic active layers.
非化学计量比的铜铬氧化物铜铁矿近来因其高p型电导率和在可见光范围内足够的光学透过率而备受关注。然而，为了适用于诸如p-n结、晶体管或光电器件等有源器件，必须有效地调整其电子特性。在此，沉积后退火处理被证明是一种精确控制这种先前简并半导体材料电学性质的合适方法。使用两种不同的方法研究了退火过程的能量学，分别作为退火温度和退火时间的函数，从而能够准确确定缺陷退火的激活能。通过使用这种方法，电载流子浓度在10^19 - 10^22 cm^-3范围内变化，而记录的漂移迁移率变化涵盖了三个数量级。此外，我们展示了精确操纵此类材料费米能级的能力，这对于控制光电器件有源层中的载流子注入和提取非常重要。
