Dilova Tina, Dikovska Anna, Baeva Aleksandra, Atanasova Genoveva, Avdeev Georgi, Genova Tsanislava, Nedyalkov Nikolay
Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl.11, 1113 Sofia, Bulgaria.
Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee, 1784 Sofia, Bulgaria.
Materials (Basel). 2024 Nov 25;17(23):5773. doi: 10.3390/ma17235773.
In this work, atmospheric pulsed laser deposition was used to prepare photosensitive elements. This technology is a practical and relatively inexpensive way of obtaining highly porous nanostructures composed of nanoparticles or nanoaggregates characterized by a large surface-to-volume ratio. Samples were produced via laser nanosecond or picosecond laser ablation of pure ZnO or mixed ZnO-TiO targets on quartz substrates with pre-deposited gold electrodes. The structure, morphology, optical, and electrical properties of the nanostructures obtained were studied regarding the sample composition and laser ablation regime applied. The ablation of a mixed ZnO-TiO target led to the fabrication of composite samples consisting of ZnO and ZnTiO nanoparticles. The electrical properties of pure and composite samples were studied under exposure to UV light irradiation. It was found that the photosensitive properties of the samples depended on the ablation regime applied. The dark current measured for the nanosecond-deposited samples was a few nA, which was an order of magnitude larger compared to the picosecond-deposited samples. The value of the photogenerated current of the nanosecond-deposited samples was 10-times higher than that of the picosecond-deposited samples. This is due to the lower absorption of the picosecond-deposited samples, as well as to the presence of defect-related radiative recombination in the picosecond-deposited samples, which limits the photocurrent rise. The estimated rise and decay times were longer for the composite samples independently of the deposition regime applied.
在这项工作中，采用大气脉冲激光沉积法制备光敏元件。该技术是一种实用且相对廉价的方法，可用于获得由具有大的表面积与体积比的纳米颗粒或纳米聚集体组成的高度多孔纳米结构。通过在预沉积金电极的石英衬底上对纯ZnO或混合ZnO-TiO靶材进行纳秒或皮秒激光烧蚀来制备样品。针对所获得的纳米结构的样品组成和应用的激光烧蚀方式，研究了其结构、形态、光学和电学性质。混合ZnO-TiO靶材的烧蚀导致制备出由ZnO和ZnTiO纳米颗粒组成的复合样品。在紫外光照射下研究了纯样品和复合样品的电学性质。发现样品的光敏性质取决于所应用的烧蚀方式。纳秒沉积样品测得的暗电流为几纳安，与皮秒沉积样品相比大一个数量级。纳秒沉积样品的光生电流值比皮秒沉积样品高10倍。这是由于皮秒沉积样品的吸收率较低，以及皮秒沉积样品中存在与缺陷相关的辐射复合，这限制了光电流的上升。无论应用何种沉积方式，复合样品的估计上升和衰减时间都更长。
