Nano-ribbon solar fuel devices

从环保，具有成本效益的太阳能电池产生的能量提供了一个可持续的解决方案，以满足日益增长的全球能源需求。因此，研究人员专注于使用高效，环保，地球丰富的吸收材料（如金属硫化物和硒化物）开发薄膜太阳能电池。与其他新兴化合物相比，硒化锑（Sb_2Se_3）由于具有相化学简单、物理化学稳定性高、带隙合适、载流子迁移率高和吸收系数高等优点，在光化学领域中作为一种有前途的光活性材料受到了极大的关注。制备Sb 2 Se 3薄膜的物理化学方法有快速热蒸发法、磁控溅射法、近距离升华法、电沉积法、原子层沉积法等。（Sb_4Se_6）_n带具有不同生长取向（横向和垂直生长模式），其由于其复杂的微结构而难以控制。在（Sb 4Se 6）n一维链状结构中，原子以共价键结合，而条带通过货车范德华力相互连接。这导致载流子沿着（Sb 4Se 6）n带的迁移比带之间的迁移快。为了提供改进的电荷传输并减少整个Sb 2Se 3层中的电荷复合，带应垂直于衬底取向。因此，控制Sb_2Se_3薄膜中（Sb_4Se_6）_n条带的横向和纵向生长比例是保证载流子有效传输的关键。因此，本研究的重点是探索新的生长条件，为高效太阳能电池的最佳Sb 2Se 3纳米取向。为了分析一维纳米带的择优取向，将Sb_2Se_3沉积到氟掺杂的氧化锡（FTO）衬底上，使用RTE。为了了解Sb 2Se 3薄膜的生长机制和载流子输运行为，将通过X射线衍射、扫描电子显微镜、透射电子显微镜、表面轮廓仪和Kelvin探针力显微镜对Sb 2Se 3薄膜的结构和性能进行系统的表征和分析。此外，Sb_2Se_3薄膜对太阳能电池性能的影响也将被研究。在本文中，薄膜太阳能电池器件被配置为覆层配置，其中薄膜涂覆有缓冲层，然后以金属背接触的沉积结束（即，Au）。在本研究中用于形成具有吸收层的p-n异质结的缓冲层是n型TiO 2。然后，由于在Sb 2Se 3/TiO 2界面之间的p-n异质结处产生内置电场，光生电子从Sb 2Se 3（p型）移动到TiO 2（n型）。另一方面，光生空穴被p型空穴传输层吸引并被Au收集，这将减少背接触处的复合。最后，改性薄膜的效果将用于制造高效的水分解装置。

Energy generated from environmentally friendly, cost-effective solar cells offers a sustainable solution to meet the increasing global energy demand. Hence, researchers are focused on the development of thin-film solar cells using highly efficient, environmentally friendly, earth-abundant absorber materials like metal sulfides and selenides. Compared to other emerging compounds, antimony selenide (Sb2Se3) has gained tremendous interest as a promising photoactive material in photovoltaics due to its advantages of simplified phase chemistry, high physiochemical stability, suitable bandgap, high carrier mobility, and high absorption coefficient. Different physio-chemical methods are used to generate Sb2Se3 thin films, which include rapid thermal evaporation (RTE), magnetron sputtering, close-spaced sublimation, electrodeposition, atomic layer deposition, etc. When the Sb2Se3 thin films are deposited onto a substrate, the (Sb4Se6)n ribbons exhibit different growth orientations (lateral and vertical growth modes) which are difficult to control due to their complex microstructures. In the (Sb4Se6)n 1D chain structure, the atoms are covalently bonded, whereas ribbons are interconnected by van der Waals forces. This results in faster migration of carriers along (Sb4Se6)n ribbons than between ribbons. In order to provide improved charge transport and to reduce the charge recombination throughout the Sb2Se3 layer, the ribbons should oriented perpendicular to the substrate. Therefore, it is crucial to regulate the ratio of lateral and vertical growth of (Sb4Se6)n ribbons in Sb2Se3 thin films to ensure efficient carrier transport. Thus, this study focuses to explore novel growth conditions for optimal Sb2Se3 nanoribbon orientation for efficient solar cells. In order to analyze the preferred orientation of 1D nanoribbons, the Sb2Se3 will be deposited onto the fluorine-doped tin oxide (FTO) substrates with the use of RTE. To understand the growth mechanism and carrier transport behavior of Sb2Se3 thin films, the structure, and properties of Sb2Se3 thin films will be systematically characterized and analyzed by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, surface profilometer, and Kelvin probe force microscopy. Moreover, Sb2Se3 thin films on solar cell performance will be investigated. Herein the thin-film solar cells devices are configured in superstrate configuration where the thin film is coated with a buffer layer and then ends with the deposition of metallic back-contact (i.e., Au). The buffer used in this study to form a p-n heterojunction with an absorber layer is n-type TiO2. The photo-generated electrons then move from Sb2Se3 (p-type) to TiO2 (n-type) due to the creation of a built-in electric field at the p-n heterojunction between the Sb2Se3/TiO2 interface. On the other hand, the photo-generated holes are attracted by the p-type hole-transport layer and collected by the Au which will reduce the recombination at the back contact. Finally, the effect of the modified thin films will be used to fabricate efficient water splitting devices.