Synthesis and characterisation of hole transporting soluble polyschiff base containing triarylamine unit in the backbone

ABSTRACTIn this paper we report a method for tuning the extent of hole injection into the active light emitting tris- (8-hydroxyquinoline) aluminum (Alq3) layer in organic light emitting diodes (OLEDs). This is made possible by modifying the indium tin oxide (ITO) anode with an oxidized transport layer (OTL) comprising a hole transporting polycarbonate of N,N'-bis(3-hydroxymethyl)-N,N'-bis(phenyl) benzidine and diethylene glycol (PC-TPB-DEG) doped with varying concentrations of antimonium hexafluoride salt of N,N,N',N'-tetra-p-tolyl-4,4'-biphenyldiamine (TMTPD+ SbF6-). The conductivity of the OTL can be changed over three orders of magnitude depending on salt loading. The analysis of hole and electron current variations in these devices indicates that optimizing the conductivity of the OTL enables the modulation of hole injection into the Alq3 layer. The bipolar charge transport properties for OLEDs in which the interfacial carrier injection barriers have been minimized, are governed by the conductivities of the respective layers and in this case it is shown that the variable conductivity of the OTL does allow for better control of the same. Accordingly, varying the concentration of holes in the device indicates that beyond an optimum concentration of holes, further hole injection results in the formation of light quenching cationic species and the initiation of oxidative degradation processes in the Alq3 layer, thus accelerating the intrinsic degradation of these devices. The variable conductivity of the OTL can hence be used to minimize the occurrence of these processes.

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Dendritic core carbazole-based hole transporting materials for perovskite solar cells: molecular design, photovoltaic performance and impact of hole transporters and doping on the electrical response of the photovoltaic devices

10.29363/nanoge.iperop.2019.010 ◽

2018 ◽

Author(s):

Thanh-Tuan Bui ◽

Maria Ulfa ◽

Federica Maschietto ◽

Alistar Ottochian ◽

Mai-Phuong Nghiêm ◽

...

Keyword(s):

Solar Cells ◽

Molecular Design ◽

Electrical Response ◽

Photovoltaic Performance ◽

Perovskite Solar Cells ◽

Photovoltaic Devices ◽

Dendritic Core ◽

Hole Transporting ◽

Hole Transporting Materials

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Regulation of peripheral tert-butyl position: Approaching efficient blue OLEDs based on solution-processable hole-transporting materials

Organic Electronics ◽

10.1016/j.orgel.2019.05.005 ◽

2019 ◽

Vol 71 ◽

pp. 85-92 ◽

Cited By ~ 3

Author(s):

Sen Wu ◽

Hongli Liu ◽

Wei Sun ◽

Xianggao Li ◽

Shirong Wang

Keyword(s):

Tert Butyl ◽

Hole Transporting ◽

Solution Processable ◽

Hole Transporting Materials

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Dopant‐Free and Green‐Solvent‐Processable Hole‐Transporting Materials for Highly Efficient Inverted Planar Perovskite Solar Cells

Solar RRL ◽

10.1002/solr.202070105 ◽

2020 ◽

Vol 4 (10) ◽

pp. 2070105

Author(s):

Fei Meng ◽

Yunhao Wang ◽

Yaping Wen ◽

Xue Lai ◽

Wenhui Li ◽

...

Keyword(s):

Solar Cells ◽

Perovskite Solar Cells ◽

Green Solvent ◽

Highly Efficient ◽

Hole Transporting ◽

Hole Transporting Materials

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Effects of 5-Ammonium Valeric Acid Iodide as Additive on Methyl Ammonium Lead Iodide Perovskite Solar Cells

Nanomaterials ◽

10.3390/nano10122512 ◽

2020 ◽

Vol 10 (12) ◽

pp. 2512

Author(s):

Daming Zheng ◽

Changheng Tong ◽

Tao Zhu ◽

Yaoguang Rong ◽

Thierry Pauporté

Keyword(s):

Solar Cells ◽

Perovskite Solar Cells ◽

Single Crystal Silicon ◽

Mesoporous Structure ◽

Valeric Acid ◽

Electrical Impedance Spectroscopy ◽

Lead Iodide ◽

Crystal Silicon ◽

Time Resolved ◽

Hole Transporting

During the past decade, the power conversion efficiency (PCE) of perovskite solar cells (PSCs) has risen rapidly, and it now approaches the record for single crystal silicon solar cells. However, these devices still suffer from a problem of stability. To improve PSC stability, two approaches have been notably developed: the use of additives and/or post-treatments that can strengthen perovskite structures and the use of a nontypical architecture where three mesoporous layers, including a porous carbon backcontact without hole transporting layer, are employed. This paper focuses on 5-ammonium valeric acid iodide (5-AVAI or AVA) as an additive in methylammonium lead iodide (MAPI). By combining scanning electron microscopy (SEM), X-ray diffraction (XRD), time-resolved photoluminescence (TRPL), current–voltage measurements, ideality factor determination, and in-depth electrical impedance spectroscopy (EIS) investigations on various layers stacks structures, we discriminated the effects of a mesoscopic scaffold and an AVA additive. The AVA additive was found to decrease the bulk defects in perovskite (PVK) and boost the PVK resistance to moisture. The triple mesoporous structure was detrimental for the defects, but it improved the stability against humidity. On standard architecture, the PCE is 16.9% with the AVA additive instead of 18.1% for the control. A high stability of TiO2/ZrO2/carbon/perovskite cells was found due to both AVA and the protection by the all-inorganic scaffold. These cells achieved a PCE of 14.4% in the present work.

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Crystal Engineering Approach for Fabrication of Inverted Perovskite Solar Cell in Ambient Conditions

Energies ◽

10.3390/en14061751 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1751

Author(s):

Inga Ermanova ◽

Narges Yaghoobi Nia ◽

Enrico Lamanna ◽

Elisabetta Di Bartolomeo ◽

Evgeny Kolesnikov ◽

...

Keyword(s):

Solar Cell ◽

Crystal Engineering ◽

High Performance ◽

Perovskite Solar Cells ◽

Perovskite Solar Cell ◽

Layer By Layer ◽

Ambient Conditions ◽

Sequential Method ◽

Engineering Approach ◽

Hole Transporting

In this paper, we demonstrate the high potentialities of pristine single-cation and mixed cation/anion perovskite solar cells (PSC) fabricated by sequential method deposition in p-i-n planar architecture (ITO/NiOX/Perovskite/PCBM/BCP/Ag) in ambient conditions. We applied the crystal engineering approach for perovskite deposition to control the quality and crystallinity of the light-harvesting film. The formation of a full converted and uniform perovskite absorber layer from poriferous pre-film on a planar hole transporting layer (HTL) is one of the crucial factors for the fabrication of high-performance PSCs. We show that the in-air sequential deposited MAPbI3-based PSCs on planar nickel oxide (NiOX) permitted to obtain a Power Conversion Efficiency (PCE) exceeding 14% while the (FA,MA,Cs)Pb(I,Br)3-based PSC achieved 15.6%. In this paper we also compared the influence of transporting layers on the cell performance by testing material depositions quantity and thickness (for hole transporting layer), and conditions of deposition processes (for electron transporting layer). Moreover, we optimized second step of perovskite deposition by varying the dipping time of substrates into the MA(I,Br) solution. We have shown that the layer by layer deposition of the NiOx is the key point to improve the efficiency for inverted perovskite solar cell out of glove-box using sequential deposition method, increasing the relative efficiency of +26% with respect to reference cells.

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