Production of multicharged iron ions and application to enhancement of photo-catalytic performance invisible light region on TiO_2 thin films

在2.45GHz电子回旋共振（ECR）离子源（TAIKO装置）中，用固体材料制备了多电荷铁离子，并在电弧ECR等离子体中用反应溅射法制备了大面积的TiO_2薄膜。用Fe丝蒸发。蒸发的中性Fe原子在ECR等离子体中电离。多电荷离子从反射镜端面对着蒸发器的另一侧引出，形成多电荷离子束。在不同的实验条件下，提取的离子电流的电荷态分布（CSD）进行了研究。通过改进微波发射装置和离子束引出装置，进一步提高了离子束的强度。我们已经成功地产生了多电荷离子，最高可达Fe^<10+>。在氮化硼（BN）坩埚的情况下，氮气在1500℃以上释放。通常在Si（100）衬底上形成约100 nm的TiO_2薄膜。通过X射线衍射仪表征了TiO_2的结晶度，通过接触角的测定评价了TiO_2的光催化性能。TiO_2薄膜的晶型为金红石型和金红石型。为了提高TiO_2薄膜在可见光区的光催化性能，在Si衬底上对TiO_2薄膜进行了Fe^<3+>和N^<3+>离子注入。在约2 × 10 ~（13）cm ~（-1）的剂量下获得了最大的光催化效率<15><-2>。用荧光灯照射四小时，比较了注入前后蒸馏水在TiO_2表面的接触角。注入后的TiO_2薄膜在可见光区的光催化性能比注入前有所提高，而在紫外光区的光催化性能没有下降。

Multicharged iron ions have been produced from solid materials in a 2.45GHz electron cyclotron resonance (ECR) ion source (TAIKO device), and also large area TiO_2 thin films are individually produced by reactive sputtering in an arched ECR plasma.Production of Fe ions has been made by direct sputtering, and by Ohmic heating, i.e., evaporating with Fe filament. The vaporized neutral Fe atoms are ionized in the ECR plasma. The multicharged ions are extracted from the opposite side of mirror end against the evaporator, and then multicharged ion beam is formed. The charge-state distributions (CSD) of the extracted ion current are investigated in various experimental conditions. Magnitude of ion beams has been tried to further enhance by improving the launch of the microwave and the extractor of ion beams. We have succeeded in producing multicharged ions up to Fe^<10+>. In the case of boron nitride (BN) crucible, nitrogen gas is released above 1500℃. And then multicharged nitrogen ions also produced and can be applied to material processing.We normally form the TiO_2 thin film (〜100nm) on the Si(100) substrates. We measure the x-ray diffraction for characterization of the TiO_2 crystallinity and the contact angle of distilled water for estimation of photo-catalytic performance. The crystalline TiO_2 thin films are anatase and rutile phases. Fe^<3+> and N^<3+> ions were implanted into TiO_2 thin films on the Si substrates in order to enhance photo-catalytic performance in visible light region. The maximum efficiency of photo-catalytic performance has been obtained at the dose of about 2X10^<15> cm^<-2>. We compared contact angles of distilled water on the TiO_2 by illuminating fluorescent light for four hours before and after implantation. Photo-catalytic performance of the TiO_2 thin film in visible light region after implantation is better than that before implantation without deterioration in ultraviolet light region.