In-situ microfluidic controlled, low temperature hydrothermal growth of nanoflakes for dye-sensitized solar cells

Abstract

In this paper, an in-situ microfluidic control unit (MCU) was designed and applied in a hydrothermal synthesis process, which provides an easy way to localize liquid-phase reaction and realize selective synthesis and direct growth of nanostructures as well as their morphology, all in a low-temperature and atmospheric environment. The morphology was controlled through controlling the amount of additivities using the MCU. This achieved a facile fabrication of Al doped ZnO (AZO) nanoflakes vertically grown on flexible polymer substrates with enhanced light scattering and dye loading capabilities. Flexible DSSCs with a significant enhancement (410% compare to ZnO NRs based devices) in power conversion efficiency were obtained using AZO nanoflake photoanodes of 6 μm thick, due to the enhancement in electron mobility and reduction in recombination. This hydrothermal synthesis using the in-situ MCU provides an efficient and scalable technique to synthesize controllable nanostructures with characteristics of easy set-up, low energy consumption and low cost.

Advances in nanostructured thin film materials for solar cell applications

“…10 (c) and (d)) with highest average PCE of 4.5% was achieved. [131] The Al doped ZnO nanostructure core improved the accessible surfaces (i.e.…”

Low-Temperature Solution Process of Al-Doped ZnO Nano-flakes for Flexible Perovskite Solar Cells

“…Compared with the perovskite film on bare glass, a significant PL quenching is observed for the perovskite film deposited on the ZnO nanoflakes. This indicates the charge extraction across the interface between the perovskite and ZnO nanoflakes [36]. Compared with the non-doped ZnO, the PL of the perovskite/AZO is further quenched.…”

“…Further, the high temperature associated with sintering a TiO 2 mesoporous framework (>400 o C) to obtain a high-quality crystallization is a substantial shortcoming that limits its applications to temperature-sensitive substrates such as plastics [17]. ZnO has been considered as one of the most promising alternative materials to replace conventional TiO 2 owing to its advantages including higher bulk electron mobility with a suitable band gap and flexibility in morphology controlling, in addition to low processing temperatures [36]. The substitution of TiO 2 by ZnO as an ETL has been considered as one of most promising alternatives to reduce production cost and expand the variety of substrates for the perovskite-based solar cells [18,28].…”

“…Most recently, ZnO nanostructures with nanoplatelike morphologies have been employed to fabricate PSC because they are believed to improve device performance by suppressing light reflection and increasing light scattering. Furthermore, they possess a large surface-to-volume ratio, and when integrated with the perovskite absorber, can provide a direct continuous pathway for electron transport with minimal recombination [10,20,22,23,36]. In this regard, several previous reports focused on integrating one-dimensional (1D) ZnO (e.g., nanowires, nanorods, or nanotubes) with PSCs and different functional nanostructured-based devices have been successfully demonstrated [3,14,21,35].…”

Hierarchical Nanostructures of Titanium Dioxide: Synthesis and Applications

“…Titania nanostructures can be synthesized using various techniques. Some of them are hydrothermal [26,[29][30][31][32][33][34], solvothermal methods [10,11,35], sol-gel synthesis [1,15,36], microwave irradiation [8,24,37,38], physical and chemical vapor deposition [4,32,39], electrochemical methods [40,41] and anodization [42][43][44].…”