Elevated Photovoltaic Performance in Medium Bandgap Copolymers Composed of Indacenodi-thieno[3,2-b]thiophene and Benzothiadiazole Subunits by Modulating the π-Bridge

Two random conjugated polymers (CPs), namely, PIDTT-TBT and PIDTT-TFBT, in which indacenodithieno[3,2-b]thiophene (IDTT), 3-octylthiophene, and benzothiadiazole (BT) were in turn utilized as electron-donor (D), π-bridge, and electron-acceptor (A) units, were synthesized to comprehensively analyze the impact of reducing thiophene π-bridge and further fluorination on photostability and photovoltaic performance. Meanwhile, the control polymer PIDTT-DTBT with alternating structure was also prepared for comparison. The broadened and enhanced absorption, down-shifted highest occupied molecular orbital energy level (EHOMO), more planar molecular geometry thus enhanced the aggregation in the film state, but insignificant impact on aggregation in solution and photostability were found after both reducing thiophene π-bridge in PIDTT-TBT and further fluorination in PIDTT-TFBT. Consequently, PIDTT-TBT-based device showed 185% increased PCE of 5.84% profited by synergistically elevated VOC, JSC, and FF than those of its counterpart PIDTT-DTBT, and this improvement was chiefly ascribed to the improved absorption, deepened EHOMO, raised μh and more balanced μh/μe, and optimized morphology of photoactive layer. However, the dropped PCE was observed after further fluorination in PIDTT-TFBT, which was mainly restricted by undesired morphology for photoactive layer as a result of strong aggregation even if in the condition of the upshifted VOC. Our preliminary results can demonstrate that modulating the π-bridge in polymer backbone was an effective method with the aim to enhance the performance for solar cell.

Microstructure and Property Calculation of Three Typical Second Generation Single Crystal Superalloys

To theoretically evaluate three widely used second generation single crystal superalloys-PWA1484, ReneN5 and DD6, the alloy densities, phase graphs, TCP contents, d-electron energy, and creep rupture lives were calculated, and the calculation results were analyzed combined with actual data. Results showed that among the three alloys, PWA1484 had the greatest density, secondly was DD6, and ReneN5’s density was the lowest. The PWA1484 alloy was most likely to precipitate TCP due to its highest d-orbital energy level; the ReneN5 alloy had a medium d-orbital energy level, but its high Cr content induced it to precipitate the most TCP types; the DD6 alloy had the least chance to precipitate TCP phases because of its lowest d-orbital energy level as well as lowest Cr content. It is concluded that thermodynamic calculation had the ability to simulate TCP types and TCP content at steady states, while d-orbital energy concept was capable of exhibiting the alloys in sequence of TCP precipitation potential. Mere thermodynamic calculation will lead to comparatively conservative results, including more TCP types, higher TCP contents and lower rupture lives. Analyzing the thermodynamic and d-orbital energy calculations comprehensively, it can be considered that the DD6 alloy has the most stable microstructure among the three single crystal superalloys.

Dithiolate Mixed with Diimine and it's Metal Effects on Sensors

Determination of the two Maleinitriledithiolate • phenanthroline-5 ,6-dione Lynn mixed copper (II), zinc (II) complexes MLL' (L=mnty, 1,2 twelve dicyanoethylene-1,2 - thiol ion L '= phen-5, 6-dione, l, 10 - phenanthroline-5 ,6-one o) amine in dimethy-l phthalate (DMF), acetone (Acet.) and chloroform (HCli) electronic absorption spectra corresponding to transitions studied the relationship between the absorption bands in the electronic spectra associated molecular orbital energy level diagram to explore their photographic oxidation characteristics in DMF.

Studies on the Geometric and Electronic Structures of SiC Polytypes

SiC poly-type geometric structure, electronic structure and energy have been subjected to systematic study based on first principle calculation method given in density functional theory. After calculation, the energy results show that 4H-SiC system energy is the lowest and stablest, while 2H-SiC system energy is the highest and unstablest; the calculation results of the band structure show that six SiC poly-types are indirect wide band gap semiconductor, with valence band top on point Γ of Brillouin zone, conduction band bottom on point M of Brillouin zone; with the increase of hexagonality, the energy gap and valence band width are gradually getting smaller, with largest splitting of orbital energy level on 2H-SiC valence band top, reaching to 0.122 eV, while the splitting of orbital energy level on 8H-SiC valence band top is the smallest, with 0.027 eV only.