Morphology Controlling of All‐Inorganic Perovskite at Low Temperature for Efficient Rigid and Flexible Solar Cells

Abstract

organic components with inorganic cations such as cesium (Cs + ) and rubidium (Rb + ) ions can effectively improve the thermal stability. Recently, all-inorganic cesium lead halide perovskites (CsPbX 3 , X = I, Br, Cl, or mixed halides), which have higher melting points (in excess of 460 °C), [10] have been investigated as thermal stable photoabsorption materials. The CsPbI 2 Br perovskites, which possess a reasonable bandgap of 1.9 eV and considerable phase stability, were emphasized as the main research subject in previous work. [24][25][26][27][28][29][30] To improve the performance of CsPbX 3 -based PSCs, a series of work on composition [18,19] and fabrication [20][21][22][23][24] engineerings have been intensely carried out. Unfortunately, the CsPbX 3 perovskites generally require high-temperature annealing (>250 °C) to form black photovoltaic-active cubic phase, [27][28][29][30] which is energy-consuming and undesirable for multijunction tandem and flexible solar cells. Up to now, it is still challenging to obtain uniform and void-free CsPbX 3 perovskite films via low-temperature solution-processed methods, let alone room temperature (RT) based technologies.In this work, we demonstrate that coordinated solvent dimethylsulphoxide (DMSO) can effectively induce the RT formation of photovoltaic-active CsPbX 3 perovskites, and a simple RT solvent (DMSO) annealing (RTSA) treatment can controllably remove the high boiling point DMSO and result in highly uniform and void-free CsPbX 3 perovskite films, as well as a postannealing treatment at the moderate temperature of 120 °C can further improve the perovskite grain size and crystallinity. These results provide an approach to prepare high quality allinorganic CsPbX 3 perovskite films at RT or a relatively low temperature (<120 °C). Consequently, efficient inverted CsPbI 2 Brbased PSCs were achieved on both glass and flexible substrates.As previously reported, [27] the CsPbI 2 Br perovskite precursor solution in N,N-dimethylformamide (DMF) suffers from a low concentration (≈0.43 m) due to the solubility limitation of bromide. While for the perovskite precursor solution with DMSO as solvent, the stronger coordination interaction between DMSO and the perovskite precursor enables the concentration exceeding 2 m ( Figure S1, Supporting Information), resulting in thicker perovskite films with sufficient light absorption ( Figure S2, Supporting Information). Furthermore, All-inorganic cesium lead halide (CsPbX 3 ) perovskites have emerged as promising photovoltaic materials owing to their superior thermal stability compared to traditional organic-inorganic hybrid counterparts. However, the CsPbX 3 perovskites generally need to be prepared at high-temperature, which restricts their application in multilayer or flexible solar cells. Herein, the formation of CsPbX 3 perovskites at room-temperature (RT) induced by dimethylsulphoxide (DMSO) coordination is reported. It is further found that a RT solvent (DMSO) annealing (RTSA) treatment is valid to control the perovskite cryst...

Grain Boundary Enhanced Photoluminescence Anisotropy in Two‐Dimensional Hybrid Perovskite Films

“…The corresponding periodicity caculated from the XRD patterns is 15.7 Å, which is in accordance with the interlayer distance of (PEA) 2 PbI 4 from previous report . However, the microscopic morphologies of two films are quite different from each other, as illustrated by the cross‐sectional scanning electron microscope (SEM) images in Figure c,d. The crystal grains of hot‐cast film are apparently smaller compared with those of as‐cast film, although the film thickness is ≈ 350 nm for both samples.…”

Inorganic CsPbI2Br Perovskite Solar Cells: The Progress and Perspective

“…Besides, the facile‐deposited CsPbI 2 Br films exhibit excellent long‐term phase stability and thermal stability. Recently, Rao et al found the as‐deposited non‐perovskite CsPbI 2 Br film rapidly transforms into black cubic phase through a room‐temperature solvent (DMSO) annealing (RTSA) treatment (Figure a) . The solar cells from the room‐temperature‐deposited CsPbI 2 Br film exhibit a maximum PCE of 6.4%, while the efficiency boosts up to 10.4% after the RTSA‐treated CsPbI 2 Br film sintered at low‐temperature of 120 °C.…”

“…A photography of the flexible solar cell is given as inset. Reproduced with permission . Copyright 2018, Wiley–VCH.…”

High Performance Flexible Transparent Electrode via One‐Step Multifunctional Treatment for Ag Nanonetwork Composites Semi‐Embedded in Low‐Temperature‐Processed Substrate for Highly Performed Organic Photovoltaics

“…While flexible electronics have become emerging technologies for various applications such as solar cells, displays, thin‐film transistors, sensors, and power generating window, [ 1–15 ] flexible transparent electrodes need to fulfill the requirements of high transparency, good conductivity, efficient charge transportation to adjacent layers, and robust electrical stability under simultaneously continuous operation bias and mechanical bending. Among various flexible electrodes such as graphene, [ 16,17 ] carbon nanotube, [ 18 ] metallic nanowire, [ 19–21 ] conductive polymer [ 22 ] and their combination, [ 23–25 ] silver nanowire (AgNW)‐based electrode is one of the attractive candidates.…”