scholarly journals High performance polyimide films containing benzimidazole moieties for thin film solar cells

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 555-562 ◽  
Author(s):  
Pengchang Ma ◽  
Chuntao Dai ◽  
Hongbo Liu
Keyword(s):  
Thin Film ◽  
Thermal Expansion ◽  
Solar Cell ◽  
High Performance ◽  
Printed Circuit Boards ◽  
Moisture Absorption ◽  
Flexible Substrate ◽  
Tensile Modulus ◽  
Thermal Imidization ◽  
Flexible Printed Circuit

AbstractIn order to match the fabrication process of flexible Copper-Indium-Gallium-Selenide (CIGS) solar cell, a series of polyimides (PIs) with high initial decomposition temperatures (Td) were prepared from 6,4′-diamino-2′-trifluoromethyl-2-phenylbenzimidazole (DATFPBI), p-phenylenediamine (p-PPD), and S-type biphenyl dianhydride (s-BPDA) using a sequential copolymerization, casting, and thermal imidization process. The physical properties of the PIs were found to be effectively modified by adjusting both the ratio of the rigid momomers and the thermal imidization process. With the introduction of DATFPBI, the polymers showed significant improvements in thermal stability, thermal expansion, moisture absorption and mechanical properties. PIPBId, one of the synthesized PI film, exhibited an excellent comprehensive performance: a glass transition temperature of 368°C, a tensile modulus of 6.8 GPa, a linar coefficient thermal expansion (CTE) of 16.8 ppm/K, and a moisture absorption of 1.42%. Furthermore, Td of this thin film was up to 524°C,which indicated that the PIPBId film is a competitive candidate as the flexible substrate for CIGS, Copper-Zinc-Tin-Sulphide (CZTS) solar cell and flexible printed circuit boards (FPCB) where high process temperature is necessary.

scholarly journals Poly(ester imide)s Possessing Low Coefficients of Thermal Expansion and Low Water Absorption (V). Effects of Ester-linked Diamines with Different Lengths and Substituents

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 859 ◽  
Author(s):  
Masatoshi Hasegawa ◽  
Tomoaki Hishiki
Keyword(s):  
Thermal Expansion ◽  
High Performance ◽  
Printed Circuit Boards ◽  
Dielectric Substrate ◽  
Amic Acid ◽  
Substrate Material ◽  
Polymerization Process ◽  
Molecular Weights ◽  
Flexible Printed Circuit ◽  
Biphenyltetracarboxylic Dianhydride

A series of ester-linked diamines, with different lengths and substituents, was synthesized to obtain poly(ester imide)s (PEsIs) having improved properties. A substituent-free ester-linked diamine (AB-HQ) was poorly soluble in N-methyl-2-pyrrolidone at room temperature, which forced the need for polyaddition by adding tetracarboxylic dianhydride solid into a hot diamine solution. This procedure enabled the smooth progress of polymerization, however, accompanied by a significant decrease in the molecular weights of poly(amic acid)s (PAAs), particularly when using hydrolytically less stable pyromellitic dianhydride. On the other hand, the incorporation of various substituents (–CH3, –OCH3, and phenyl groups) to AB-HQ was highly effective in improving diamine solubility, which enabled the application of the simple polymerization process without the initial heating of the diamine solutions, and led to PAAs with sufficiently high molecular weights. The introduction of bulkier phenyl substituent tends to increase the coefficients of thermal expansion (CTE) of the PEsI films, in contrast to that of the small substituents (–CH3, –OCH3). The effects of ester-linked diamines, consisting of longitudinally further extended structures, were also investigated. However, this approach was unsuccessful due to the solubility problems of these diamines. Consequently, the CTE values of the PEsIs, obtained using longitudinally further extended diamines, were not as low as we had expected initially. The effects of substituent bulkiness on the target properties, and the dominant factors for water uptake (WA) and the coefficients of hygroscopic expansion (CHE), are also discussed in this study. The PEsI derived from methoxy-sustituted AB-HQ analog and 3,3′,4,4′-biphenyltetracarboxylic dianhydride achieved well-balanced properties, i.e., a very high Tg (424 °C), a very low CTE (5.6 ppm K−1), a low WA (0.41%), a very low CHE value (3.1 ppm/RH%), and sufficient ductility, although the 26 μm-thick film narrowly missed certification of the V-0 standard in the UL-94V test. This PEsI film also displayed a moderate εr (3.18) and a low tan δ (3.14 × 10−3) at 10 GHz under 50% RH and at 23 °C. Thus, this PEsI system is a promising candidate as a novel dielectric substrate material for use in the next generation of high-performance flexible printed circuit boards operating at higher frequencies (≥10 GHz).

scholarly journals Elaboration of Conductive Polymer thin films (P3HT/PCBM) by spin coating method – Application for hybrid organic solar cell

2014 ◽  
Vol 17 (3) ◽  
pp. 30-40
Author(s):  
Son Hoang Cao Tran ◽  
Quoc Kien Quoc ◽  
Nhan Thuc Chi Ha ◽  
Top Khac Le ◽  
Thang Bach Phan ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
Spin Coating ◽  
High Performance ◽  
Short Circuit ◽  
Rotational Velocity ◽  
Conductive Polymer ◽  
Spin Coating Method ◽  
Donor And Acceptor ◽  
Coating Method

The nanostructured polymer-fullerene thin film is one of the most prominent materials to make the hybrid bulk heterojunction solar cell (BHJ) with high conversion efficiency. Especially when the blend of P3HT and PCBM was used as the donor and acceptor materials. The properties of P3HT and PCBM layer in solar cell has been much studied and considered as high performance systems. One of the important factors for the high performance device is the fabrication  of photo active layer with the appropriate thickness and morphology. In the ideal case, the intermolecular distance between the polymer and fullerene should be approximately 10-20 nm (the exciton diffusion distance) giving an area of extensive contact between the two phases. After the dissociation of carriers, the two polymer phases should create the path way for carriers to reach electrodes. But so far, this ideal configuration has not been published. In this work, we’ve elaborated the P3HT and PCBM photo active layers by spin coating methodon glass substrates covered ITO electrode. The rotational velocity was determined to get the necessary effective thickness of the polymer film. The annealing effect on structure, optical and electrical properties of the polymer thin film with different content of PCBM were also investigated. The experiments show the best device on electrode ITO has I-V characteristic as a photodiode and short circuit current (Isc) aboutmili-Ampere. These results demonstrate convincingly that polymer layers elaborated by spin coating method can result a good performance of the device.

Pinning down high-performance Cu-chalcogenides as thin-film solar cell absorbers: A successive screening approach

2016 ◽  
Vol 144 (19) ◽  
pp. 194706 ◽  
Author(s):  
Yubo Zhang ◽  
Youwei Wang ◽  
Jiawei Zhang ◽  
Lili Xi ◽  
Peihong Zhang ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
Thin Film Solar Cell ◽  
High Performance ◽  
Screening Approach

High-performance and low-voltage pentacene thin film transistors fabricated on the flexible substrate

2007 ◽  
Vol 22 (7) ◽  
pp. 691-694 ◽  
Author(s):  
Chang Su Kim ◽  
Sung Jin Jo ◽  
Jong Bok Kim ◽  
Seung Yoon Ryu ◽  
Joo Hyon Noh ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
High Performance ◽  
Low Voltage ◽  
Flexible Substrate

A Study of Back Electrode Stacked With Low Cost Reflective Layers For High-Efficiency Thin-Film Silicon Solar Cell

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Tsung-Wei Chang ◽  
Chao-Te Liu ◽  
Wen-Hsi Lee ◽  
Yu-Jen Hsiao
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
High Performance ◽  
Silicon Solar Cell ◽  
High Efficiency ◽  
Low Cost ◽  
Visible Region ◽  
Particle Diameter ◽  
Solid Content ◽  
Thin Film Silicon

In this study, commercially available white paint is used as a pigmented dielectric reflector (PDR) in the fabrication of a low-cost back electrode stack with an Al-doped ZnO (AZO) layer for thin-film silicon solar cell applications. An initial AZO film was deposited by the radio-frequency magnetron sputtering method. In order to obtain the highest transmittance and lowest resistivity of AZO film, process parameters such as sputtering power and substrate temperature were investigated. The optimal 100-nm-thick AZO film with low resistivity and high transmittance in the visible region are 6.4 × 10−3 Ω·cm and above 80%, respectively. Using glue-like white paint doped withTiO2 nanoparticles as the PDR enhances the external quantum efficiency (EQE) of a microcrystalline silicon absorptive layer owing to the doped white particles improving Fabry–Pérot interference (FPI), which raises reflectance and scattering ability. To realize the cost down requirement, decreasing the noble metal film thickness such as a 30-nm-thick silver reflector film, and a small doping particle diameter (D50 = 135 nm) and a high solid content (20%) lead to FPI improvement and a great EQE, which is attributed to improved scattering and reflectivity because of optimum diameter (Dopt) and thicker PDR film. The results indicate that white paint can be used as a reflector coating in low-cost back-electrode structures in high-performance electronics.

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