Cu掺杂ZnO化合物半导体薄膜的紫外-可见光双波段光电响应机理

Due to the fact that enhanced sensitivity of ZnO for visible light can be realized via the involvement of photosensitive transiton metal copper ions in the lattice of ZnO, this project intends to develop a single ZnO:Cu material to realize an integrated double-band detecting functionality for untraviolet(UV) and visible light. First, colloidal chemistry process to prepare ZnO:Cu nanocrystals (NCs) have been established and through non-equilibrium kinetic investigation on NCs growth, component and size control of NCs could be achieved. Second, based on an investigation of valence-variable copper ions and its defect states, a specific energy band regulation mechanism will be confirmed, and used to tune photosensitive level by means of defect density control. Third, in view of various film forming ability after ligands modification, an uniform and compact ZnO:Cu nanocrystalline film without no sencondary phases or precipitates can be obtained combined with spin-coating and post-annealing optimization. A general rule of influencing carrier transport and exciton lifetime will be extracted using different ligands and annealing parameters. Finally, according to the stabilization of doping process, structurally designed prototype device will be realized.Continuous response test will be also conducted in ZnO:Cu-based photodetector within the range of UV and visible-light. When the device is set at different biases, it will switch operating mode corresponding to a certain type of double-band. This will help us lay foundation on UV and visible light double-band/channel detector via a single ZnO:Cu material.

本项目通过在ZnO晶格中引入具有光敏活性的过渡金属族Cu离子杂质，提高ZnO对可见光的敏感程度，实现基于ZnO:Cu同一种材料的紫外-可见光双波段探测功能。建立胶体化学合成ZnO:Cu纳米晶工艺，通过非平衡生长动力学研究，实现纳米晶组分和晶粒尺寸的可控生长；研究不同价态Cu离子掺杂及其缺陷态对ZnO纳米晶能带调节的机理，通过缺陷态密度调控提高材料的光敏感度；研究纳米晶薄膜在不同配体修饰后的成膜特性，结合旋涂和后期热处理制备出均匀致密且无分相的ZnO:Cu纳米晶薄膜，掌握不同配体和退火工艺对载流子输运和激子寿命的影响规律；在掺杂组分稳定调控的基础上，进行探测器的结构设计，研究不同波长下的连续响应特性，获得不同Cu掺杂量下双波段的最优响应峰值，在不同偏压下实现双通道模式的转换，为研制基于同一种材料实现紫外-可见光双波段的光电探测器奠定基础。

本项目在ZnO晶格中引入具有光敏活性的过渡金属族Cu离子杂质，提高ZnO对可见光的敏感程度，实现基于ZnO:Cu同一种材料的紫外-可见光双波段探测功能。通过胶体化学合成ZnO:Cu纳米晶工艺，研究非平衡生长动力学基础上，实现了纳米晶组分和晶粒尺寸的可控生长；研究不同价态Cu离子掺杂及其缺陷态对ZnO纳米晶能带调节的机理，通过缺陷态密度调控提高材料的光敏感度；研究了纳米晶薄膜在不同配体修饰后的成膜特性，结合旋涂和后期热处理制备出均匀致密且无分相的ZnO:Cu纳米晶薄膜，总结出不同配体和退火工艺对载流子输运和激子寿命的影响规律；在掺杂组分稳定调控的基础上，设计探测器的结构，研究了不同波长下的连续响应特性，获得不同Cu掺杂量下双波段的最优响应峰值，在不同偏压下实现双通道模式的转换，为研制基于同一种材料实现紫外-可见光双波段的光电探测器奠定基础。