摘要
用阴极电沉积法制备高质量ZnO纳米薄膜,电沉积采用含有不同浓度的ZnCl2的非水二甲基亚砜溶液做电解液,室温下恒流沉积,得到纳米ZnO薄膜。研究了ZnCl2浓度对薄膜结构和光学性质的影响。沉积薄膜的ZnO粒径尺寸分别为9 8,10 4,14 5nm,随着ZnCl2浓度的增加而增大。薄膜的可见光致发光谱以紫外的自由激子发射为主。研究表明:以浓度为0 03mol/L的ZnCl2电解液制备的ZnO薄膜光学性质最好。
ZnO film is of great interest for shortwavelength optoelectronic application because ZnO semiconductor with a wide band gap of 334eV has a large exciton binding energy of 60meV at room temperature. At present,there have been many different techniques used to prepare nanocrystalline ZnO films such as molecular beam epitaxy,vapor phase deposition,and pulsed laser deposition.In this paper nanocrystalline ZnO films have been grown by a simple method of cathodic electrodeposition. Preparation of ZnO films using this method presents several advantages such as relatively high deposition rate,low deposition temperature,and low equipment cost. Cathodic electrodeposition has been widely used to deposit ZnO micrometer size particles,while little has been reported on the deposition of ZnO nanoparticles by cathodic electrodeposition on Si substrate.In this paper dimethylsulfoxide (DMSO) solutions containing ZnCl2 is introduced to get OH free ZnO films. Furthermore Si wafers were used as the substrates,which is of considerable interest to the optoelectronic integration.Deposition is carried out in DMSO solutions containing ZnCl2 with different concentration from 001mol/L to 005mol/L on Si substrates at room temperature. The grown films were characterized by means of ex situ techniques:Xray diffraction,atom force microscopy,infrared spectroscopy and photoluminescence spectroscopy. The effects of ZnCl2 concentration on the structural and optical properties of the films have been studied. The mean grain size of the samples,which increases with the increase of ZnCl2 concentration are 98, 104 and 145nm,respectively.The photoluminescence spectra of all the samples show two distinct features: strong ultraviolet emission lines from ZnO free exciton and negligibly weak green emission band around 510nm,which is from deep level defect emission associated with oxygen vacancies in the ZnO lattice.The exciton emission dominated in the photoluminescence spectra.In conclusion,nanocrystalline ZnO films have been fabricated by cathodic electrodeposition on Si substrates from DMSO ZnCl2 electrolytes. The results indicate that this method is a promising way to prepare nanocrystalline ZnO films.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2003年第3期289-292,共4页
Chinese Journal of Luminescence
基金
中国科学院百人计划
国家自然科学基金(60176003)资助项目
