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21.
Toward High‐Thermoelectric‐Performance Large‐Size Nanostructured BiSbTe Alloys via Optimization of Sintering‐Temperature Distribution 下载免费PDF全文
Gang Zheng Xianli Su Xinran Li Tao Liang Hongyao Xie Xiaoyu She Yonggao Yan Ctirad Uher Mercouri G. Kanatzidis Xinfeng Tang 《Liver Transplantation》2016,6(13)
High thermoelectric performance of mechanically robust p‐type Bi2Te3‐based materials prepared by melt spinning (MS) combined with plasma‐activated sintering (PAS) method can be obtained with small, laboratory grown samples. However, large‐size samples are required for commercial applications. Here, large‐size p‐type Bi2Te3‐based ingots with 30, 40, and 60 mm in diameter are produced by MS‐PAS, and the influence of temperature distribution during the sintering process on the composition and thermoelectric properties is systematically studied for the first time. Room‐temperature scanning Seebeck Microprobe results show that the large‐size ingot is inhomogeneous, induced by ellipsoidal‐shape‐distributed temperature field during the sintering process, which is verified by finite‐element analysis. Although some temperature differences are unavoidable in the sintering process, homogeneity and mechanical properties of ingots can be improved by appropriately extending the sintering time and design of graphite die. Samples cut from ingots attain the peak ZT value of 1.15 at 373 K, about 17% enhancement over commercial zone‐melted samples. Moreover, the compressive and bending strengths are improved by several times as well. It is important to ascertain that large‐size p‐type Bi2Te3‐based thermoelectric materials with high thermoelectric performance can be fabricated by MS‐PAS. 相似文献
22.
Dopant‐Free Hole Transporting Polymers for High Efficiency,Environmentally Stable Perovskite Solar Cells 下载免费PDF全文
Hsueh‐Chung Liao Teck Lip Dexter Tam Peijun Guo Yilei Wu Eric F. Manley Wei Huang Nanjia Zhou Chan Myae Myae Soe Binghao Wang Michael R. Wasielewski Lin X. Chen Mercouri G. Kanatzidis Antonio Facchetti Robert P. H. Chang Tobin J. Marks 《Liver Transplantation》2016,6(16)
Over the past five years, a rapid progress in organometal‐halide perovskite solar cells has greatly influenced emerging solar energy science and technology. In perovksite solar cells, the overlying hole transporting material (HTM) is critical for achieving high power conversion efficiencies (PCEs) and for protecting the air‐sensitive perovskite active layer. This study reports the synthesis and implementation of a new polymeric HTM series based on semiconducting 4,8‐dithien‐2‐yl‐benzo[1,2‐d;4,5‐d′]bistriazole‐alt‐benzo[1,2‐b:4,5‐b′]dithiophenes (pBBTa‐BDTs), yielding high PCEs and environmentally‐stable perovskite cells. These intrinsic (dopant‐free) HTMs achieve a stabilized PCE of 12.3% in simple planar heterojunction cells—the highest value to date for a polymeric intrinsic HTM. This high performance is attributed to efficient hole extraction/collection (the most efficient pBBTa‐BDT is highly ordered and orients π‐face‐down on the perovskite surface) and balanced electron/hole transport. The smooth, conformal polymer coatings suppress aerobic perovskite film degradation, significantly enhancing the solar cell 85 °C/65% RH PCE stability versus typical molecular HTMs. 相似文献
23.
The methanothermal reactions of M(CO)6 (M = Mo, W) with Na2S2 gave a series of homonuclear clusters [{M(CO)4}n(MS4)]2− (M=Mo, W; N=1, 2), i.e. (Ph4P)2[(CO)4Mo(MoS4)] (I), (Ph4P)2[(CO)4W(WS4)] (II), (Ph4P)2[(CO)4Mo(MoS4)Mo(CO)4] (III) and (Ph4P)2[(CO)4W(WS4)W(CO)4] (IV). The two dimers, I and II, as well as the two trimers, III and IV, are isostructural to each other, respectively. All compounds crystallize in the triclinic space group
with Z=2. The cell dimensions are: a=12.393(8), b=19.303(9), c=11.909(6) Å, =102.39(5), β=111.54(5), γ=73.61(5)°, V=2522(3) Å3 at T=23 °C for I; a=12.390(3), b=19.314(4), c=11.866(2) Å, =102.66(2), β=111.49(1), γ=73.40(2)°, V=2511(1) Å3 at T=23 °C for II; a=11.416(3), b=22.524(4), c=10.815(4) Å, =91.03(2), β=100.57(3), γ=88.96(2)°, V=2733(1) Å3 at T=−100 °C for III, a=11.498(1), b=22.600(4), c=10.864(3) Å, =90.92(2), β=100.85(1), γ=88.58(1)°, V=2771(2) Å3 at T=23 °C for IV. The dimers are each formed by the coordination of the tetrathiometalate as a bidentate chelating ligand to an M(CO)4 fragment while addition of another M(CO)4 fragment to the dimers results in the trimers. All compounds contain both tetrahedral and octahedral metal centers with the formal 6+ and 0 oxidation states, respectively. 相似文献