磁控反应溅射直接生长绒面H化Ga掺杂ZnO-TCO薄膜及其特性研究

Development of natively textured hydrogenated Ga-doped ZnO-TCO thin films for solar cells via magnetron reactive sputtering

采用直流磁控溅射技术,在玻璃衬底上直接生长出了具有绒面结构的H化Ga掺杂ZnO(HGZO)薄膜。研究了H2流量对薄膜结构、表面形貌及光电特性的影响。实验表明,在溅射过程中引入H2明显改善HGZO薄膜电学性能,并且能够直接获得具有绒面结构的薄膜。在H2流量为2.0sccm时,所制备的HGZO薄膜具有特征尺寸约200nm的类金字塔状表面形貌,同时薄膜方阻为4.8Ω,电阻率达到8.77×10-4Ω.cm。H2的引入可以明显改善薄膜短波区域的光学透过,生长获得的HGZO薄膜可见光区域平均透过率优于85%,近红外区域波长到1 100nm时仍可达80%。为了进一步提高薄膜光散射能力和光学透过率,根据不同H2流量下HGZO薄膜性能的优点,提出了梯度H2技术生长HGZO薄膜;采用梯度H2工艺生长获得的HGZO薄膜长波区域透过率有了一定的提高,薄膜具有弹坑状表面形貌,并且其光散射能力有了明显提高。

Natively textured hydrogenated gallium-doped zinc oxide（HGZO） thin films were deposited via direct current（DC） magnetron sputtering on glass substrates at the substrate temperature of 280 ℃.These natively textured HGZO thin films exhibit high optical transmittance（over 80%） in the visible and near infrared region（λ～380-1 100 nm） and excellent electrical properties.The as-grown optimized HGZO thin films with pyramid-like textured surface obtained at the hydrogen flow rate of ～2.0 sccm exhibit a relative low sheet resistance of ～4.8 Ω and resistivity of 8.77×10-4 Ω·cm.The influence of hydrogen flow rate on the surface morphology,electrical and optical properties for HGZO thin films is investigated in detail.We put forward a method of gradient H2 for growing HGZO thin films so as to obtain good create-like feature size and high optical transmittance as well as high electrical conductivity.