Triaxial Perovskite Composite Fibers Spinning the Way to Flexible Solar Cells

Abstract

Hybrid halide perovskites have made significant progress in achievably high photoconversion efficiencies (>25%) and stability as a function of their chemical engineering realized by isomorphous substitution at all three sites in AMX3 composition. Whereas the focus of current research lies on planar (2D) devices, this work brings forth an innovative structural engineering concept based on direct electrospinning of the three major perovskite solar cell components, namely, photoabsorber, hole, and electron transport materials, as continuous single triaxial fibers of μm radial dimensions (<5 μm). These perovskite fibers lay the foundation of materials engineering for fabricating tiny solar cells, which can either be woven into fabrics or incorporated as single fibers to power wearables and a variety of devices or sensors, forming the internet of things. The structures of the here presented coaxial CuSCN/MAPbI3 (MA = CH3NH3 +) and triaxial CuSCN/MAPbI3/ZnO‐Zn(OAc)2 composite fibers are verified by X‐ray diffraction data and electron microscopy coupled with energy dispersive spectroscopy and cross‐sectional analysis with focused ion beam. This work demonstrates the first report where the entire photovoltaic (PV) device and material configuration are achieved as concentric axial cables fabricated via single‐step electrospinning process.

Influence of Electrospinning Setup Parameters on Properties of Polymer-Perovskite Nanofibers

“…Electrospun nanofibers have attracted a lot of attention in scientific and industrial communities due to their unique properties, such as light weight, flexibility, controllable properties, and low cost, which have allowed them to be widely applied in many fields, e.g., energy generation and storage, sensors, drug delivery, filtration, etc. [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. The type of material (i.e., polymers and/or additives) and its properties (optical, electrical, mechanical, etc.)…”

“…The type of material (i.e., polymers and/or additives) and its properties (optical, electrical, mechanical, etc.) determine their application area [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. The properties of nanofibers can be optimized by manipulating their thickness, diameter, and orientation of nanofibers (their structure) [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ].…”

“…Beads and drops lead to inhomogeneous properties of nanofibers and could result in a strong drop in their properties [ 17 , 18 , 19 ]. The structure of nanofibers can be controlled by various parameters related to the electrospinning setup (e.g., an electrical voltage, a working distance, a feed rate, a needle diameter, and a collector type), the electrospinning solution, and the surrounding environment [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. Thus, controlling electrospinning parameters is crucial for the optimal utilization of nanofibers.…”

Effects of Adding Alkali Metals and Organic Cations to Cu-Based Perovskite Solar Cells

“…Here, additives such as copper (Cu), sodium (Na), and ethyl ammonium (EA) were examined. Cu compounds such as copper thiocyanate (CuSCN), copper oxides, (Cu x O), and copper iodide, were mainly used as hole-transport materials that replaced organic versions [9][10][11][12][13][14]. Although there have been many reports on the addition of alkali metals to perovskite precursor solutions [15][16][17][18][19][20][21][22][23], relatively few reported on the addition of Cu [24][25][26][27].…”

Effects of Co-Addition of Copper, Sodium and Ethylammonium to CH3NH3PbI3 Perovskite Compound

“…In this study, copper (Cu), sodium (Na) and ethylammonium (EA) were focused on. Cu compounds are mainly used as hole transport materials, such as copper thiocyanate (CuSCN) and copper oxide (CuO or Cu2O), which are expected to be stable inorganic hole transport materials that can replace organic hole transport materials [1][2][3][4][5]. Many studies have been reported on the addition of alkali metals to perovskite precursor solutions [6][7][8][9][10][11], but relatively few studies have been reported on the addition of copper [12][13][14][15].…”