Developing a deeper understanding of doping and defects in metal oxide semiconductors

金属氧化物(MO)半导体在许多技术平台中发挥着至关重要的作用，从大面积电子/显示器到生物传感和光催化等各种应用。总体而言，MOS提供了一系列具有可调电子性能的材料，包括载流子迁移率和密度、高光学透明度，并提供了大量稳定的纳米结构。此外，通过替代掺杂可以进一步调整MOS的电学和光学性质。在这里，我们建议研究几种n型MOS，包括In2O3SnO2，ZnO和WO3以及它们的掺杂类似物，它们是通过已建立的化学和物理沉积工艺制备的，包括原子层沉积(ALD)、化学气相沉积(CVD)和新兴的基于溶液的工艺，所有这些都在&lt；450℃。虽然不同的合成方法应该导致成分相似的薄膜，但我们预计缺陷化学和相应的电学和光学性能会有很大的变化。利用这个合作研究项目中可用的表征工具，我们旨在解决一些相关的研究问题，即：-如何通过替代掺杂实现稳定和可控的自由电子浓度？-我们能否增强和/或抑制缺陷的双重作用，即减少缺陷诱导的电荷载流子复合，但增强n型电导率？-我们能否更好地理解本征和外在掺杂对变化载流子迁移率的相互作用？-主要缺陷类型、浓度和能量如何随着工艺条件的变化而变化？

Metal oxides (MO) semiconductors play a vital role in number of technology platforms ranging from large area electronics/displays through to applications as diverse as biosensing and photocatalysis. Collectively MOs provide a suite of materials with tuneable electronic properties, including charge carrier mobility and density, high optical transparency and offer access to a plethora of stable nanostructures. Furthermore, the electrical and optical properties of MOs can be further tuned by substitutional doping.Here we propose to investigate several n-type MOs, including In2O3 SnO2, ZnO and WO3 as well as their doped analogues Fabricated by established chemical and physical deposition processes, including atomic layer deposition (ALD), chemical vapour deposition (CVD) and by emerging solution based processes all at temperatures < 450 C. Whilst the different synthetic approaches should result in compositionally similar films, we anticipate significant variation in defect chemistry and correspondingly differences in electrical and optical properties. Using the characterisation tools available in this collaborative research project we aim to address a number of interrelated research questions, namely:- How can stable and controllable free electron concentrations be achieved through substitutional doping?- Can we enhance and/or supress the dual role of defects i.e. reduce defect induced charge carrier recombination but enhance n-type conductivity?- Can we improve our understanding of the interplay between intrinsic and extrinsic dopants on change carrier mobility?- How the major defect types, their concentration and energies vary with processing conditions?