超声辅助SILAR法生长纳米晶ZnO多孔薄膜及其光学性能研究

Growth and Optical Properties of Nanocrystalline ZnO Porous Film by Ultrasonic Assisted Successive Ionic Layer Adsorption and Reaction (UA-SILAR) Method

将超声辐照技术引入连续离子层吸附与反应(SILAR)法,提出超声辅助连续离子层吸附与反应(UA-SILAR)液相成膜技术.以锌氨络离子([Zn(NH3)4]2+)溶液为前驱体,在90℃下沉积得到ZnO薄膜,对其晶体结构,微观形貌、透过光谱和光致发光性能进行表征, 并考察了超声辐照和沉积循环次数对薄膜形貌、结构和光学特性的影响.结果表明,所得薄膜由彼此交联、尺寸均匀的ZnO晶粒组成,呈现典型的多孔特征,同时具有高结晶性和强c轴取向性.由于多孔结构对入射光的散射作用,薄膜在可见光区具有低透射率(约20%);在紫外光激发下,薄膜具有较强的近带边发射和很弱的蓝带发射,体现出薄膜较高的光学质量;薄膜生长过程中超声辐照的引入可对薄膜的结晶性能和微观结构产生显著的影响.

Ultrasonic irradiation technique was introduced to the traditional successive ionic layer adsorption and reaction (SILAR) method to modify the microstructure and crystallinity of ZnO films. ZnO nanocrystalline porous films were successfully deposited on glass substrates from aqueous solution at 90 degrees C by using the precursor of [Zn(NH3)(4)](2+). Results show that as-deposited ZnO films exhibit excellent crystallinity with the preferential orientation of (002) plane. A porous feature with interconnected particles of 200 similar to 400 nm in ZnO films was observed, and each ZnO particle formed is by the aggregation of many crystallites in the size of 30 similar to 50nm. Because of the intense scattering function of the porous structure on the incident light, the films exhibit low transmittance in the visible band (similar to 20%). With the excitation of photon of 340 nm, an intense UV emission at 390 nm was observed in the PL spectra for as-deposited samples, indicating its good optical properties. The introduction of ultrasonic irradiation in the film deposition process can exert significant effects on the structure and crystallinity of ZnO films.