Two-/Three-Dimensional Perovskite Bilayer Thin Films Post-Treated with Solvent Vapor for High-Performance Perovskite Photovoltaics

Author(s):  
Rui Chen ◽  
Lening Shen ◽  
Luyao Zheng ◽  
Tao Zhu ◽  
Yanghe Liu ◽  
...  
2020 ◽  
Vol 10 (3) ◽  
pp. 350-355
Author(s):  
Yue Su ◽  
Ailing Yang ◽  
Wenzhe Zhang ◽  
Shuguang Wen

Introduction: Copolymer PBB-T with benzo[1,2-d:4,5-d']bis(thiazole) (BBT) as the accepting unit and benzodithiophene (BDT) as the donor unit is a promising candidate for highperformance non-fullerene polymer solar cells (PSCs). So far optical and dielectric constants of the PBB-T are not fully known. Method: PBB-T was synthesized and thin films of PBB-T were prepared. By using the Kramers-Kronig relations and the transmission spectra of the PBB-T films, the optical and dielectric constants, including in absorption coefficient (α(λ)), extinction coefficient (κ(λ)), refractive index (n(λ)), dielectric constant (ε1(λ),ε2(λ)), band gap (Eg) and mobility of the PBB-T films were calculated and analyzed. Result: At 500 nm, α, κ, n, ε1 and ε2 are 1.65×105 cm-1, 0.46, 1.8163, 3.0 and 1.65 respectively. Eg is 2.111 eV. The hole mobility of PBB-T are 2.41×10-5 cm2 V-1 s-1 and 1.71×10-4 cm2 V-1 s-1 for the as-cast film and for the solvent vapor annealed film respectively. The results show that these optical and dielectric constants of the PBB-T films are almost independent on the thicknesses of the films, indicating our results are reliable. The features of the optical and dielectric constants show the PBB-T films are very promising candidates for high-performance non-fullerene PSCs and potential cut-off filter only permitting red and near-infrared light passing. Conclusion: These results are significant for designing optoelectronic devices related to the PBBT thin films.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Zhuang-Hao Zheng ◽  
Hua-Bin Lan ◽  
Zheng-Hua Su ◽  
Huan-Xin Peng ◽  
Jing-Ting Luo ◽  
...  

AbstractHybrid two-dimensional (2D) halide perovskites has been widely studied due to its potential application for high performance perovskite solar cells. Understanding the relationship between microstructural and opto-electronic properties is very important for fabricating high-performance 2D perovskite solar cell. In this work, the effect of solvent annealing on grain growth was investigated to enhance the efficiency of photovoltaic devices with 2D perovskite films based on (BA)2(MA)3Pb4I13 prepared by single-source thermal evaporation. Results show that solvent annealing with the introduction of solvent vapor can effectively enhance the crystallization of the (BA)2(MA)3Pb4I13 thin films and produce denser, larger-crystal grains. The thin films also display a favorable band gap of 1.896 eV, which benefits for increasing the charge-diffusion lengths. The solvent-annealed (BA)2(MA)3Pb4I13 thin-film solar cell prepared by single-source thermal evaporation shows an efficiency range of 2.54–4.67%. Thus, the proposed method can be used to prepare efficient large-area 2D perovskite solar cells.


Author(s):  
Lee D. Peachey ◽  
Lou Fodor ◽  
John C. Haselgrove ◽  
Stanley M. Dunn ◽  
Junqing Huang

Stereo pairs of electron microscope images provide valuable visual impressions of the three-dimensional nature of specimens, including biological objects. Beyond this one seeks quantitatively accurate models and measurements of the three dimensional positions and sizes of structures in the specimen. In our laboratory, we have sought to combine high resolution video cameras with high performance computer graphics systems to improve both the ease of building 3D reconstructions and the accuracy of 3D measurements, by using multiple tilt images of the same specimen tilted over a wider range of angles than can be viewed stereoscopically. Ultimately we also wish to automate the reconstruction and measurement process, and have initiated work in that direction.Figure 1 is a stereo pair of 400 kV images from a 1 micrometer thick transverse section of frog skeletal muscle stained with the Golgi stain. This stain selectively increases the density of the transverse tubular network in these muscle cells, and it is this network that we reconstruct in this example.


2020 ◽  
Author(s):  
Peiyao Wang ◽  
Bangchuan Zhao ◽  
Jin Bai ◽  
Kunzhen Li ◽  
Hongyang Ma ◽  
...  

Nanophotonics ◽  
2020 ◽  
Vol 9 (16) ◽  
pp. 4719-4728
Author(s):  
Tao Deng ◽  
Shasha Li ◽  
Yuning Li ◽  
Yang Zhang ◽  
Jingye Sun ◽  
...  

AbstractThe molybdenum disulfide (MoS2)-based photodetectors are facing two challenges: the insensitivity to polarized light and the low photoresponsivity. Herein, three-dimensional (3D) field-effect transistors (FETs) based on monolayer MoS2 were fabricated by applying a self–rolled-up technique. The unique microtubular structure makes 3D MoS2 FETs become polarization sensitive. Moreover, the microtubular structure not only offers a natural resonant microcavity to enhance the optical field inside but also increases the light-MoS2 interaction area, resulting in a higher photoresponsivity. Photoresponsivities as high as 23.8 and 2.9 A/W at 395 and 660 nm, respectively, and a comparable polarization ratio of 1.64 were obtained. The fabrication technique of the 3D MoS2 FET could be transferred to other two-dimensional materials, which is very promising for high-performance polarization-sensitive optical and optoelectronic applications.


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