Superfluid density dominated junction resistance of bulk polycrystalline YBa_(2)Cu_(3)O_(7−δ) and DyBa_(2)Cu_(3)O_(7−δ) superconductors at low temperature

Resistances of grain junctions of bulk polycrystalline YBa_(2)Cu_(3)O_(7−δ)(YBCO) and DyBa_(2)Cu_(3)O_(7−δ)(DyBCO) superconductors have been extracted following(i)Ambegaokar‐Baratoff(AB)and(ii)de Gennes(dG)equations.Current–voltage(IV)below the critical temperature(T_(c))has been used to extract transport critical current density(J_(c)).The variations of the junction resistances,(RN)with temperature(T)exhibit that below a critical value of the normalised superfluid density(NSD),junctions become very low resistive and exhibit metallicity.Dependence of this feature of RN on the energy gaps has also been explored.Weak scattering limit is found to be compatible with the maximum of RN(T)as is observed from the corresponding NSD.

High-performance single-wall carbon nanotube transparent conductive films

A single-wall carbon nanotube(SWCNT)has superior optical,electrical,and mechanical properties due to its unique structure and is therefore expected to be able to form flexible high-performance transparent conductive films(TCFs).However,the optoelectronic performance of these films needs to be improved to meet the requirements of many devices.The electrical resistivity of SWCNTTCFs is mainly determined by the intrinsic resistivity of individual SWCNTs and their junction resistance in networks.We analyze these key factors and focus on the optimization of SWCNTs and their networks,which include the diameter,length,crystallinity and electrical type of the SWCNTs,and the bundle size and interconnects in networks,as well as chemical doping and microgrid design.We conclude that isolated/small-bundle,heavily doped metallic or semiconducting SWCNTs with a large diameter,long length and high crystallinity are necessary to fabricate high-performance SWCNTTCFs.A simple,controllable way to construct macroscopic SWCNT networks with Y-type connections,welded junctions or microgrid design is important in achieving a low resistivity.Finally,some insights into the key challenges in the manufacture and use of SWCNT TCFs and their prospects are presented,hoping to shed light on promoting the practical application of SWCNT TCFs in future flexible and stretchable optoelectronics.