Regarding conventional quantum dot lightemitting diodes(QLEDs)fabricated by using the spin-coating(SC)technique,voids and interstitial spaces are inevitable due to unordered quantum dots(QDs)stacking,generating device...Regarding conventional quantum dot lightemitting diodes(QLEDs)fabricated by using the spin-coating(SC)technique,voids and interstitial spaces are inevitable due to unordered quantum dots(QDs)stacking,generating device leakage current under an external bias.In the present study,we fabricated an ultra-homogeneous and highly ordered QD monolayer by adopting the Langmuir-Blodgett(LB)technique.The QD monolayer was transferred as a emissive layer with a horizontal lifting(HL)method to a red QLED,which exhibited high performance with an external quantum efficiency(EQE)of 19.0% and lifetime(T_(95)@100 cd m^(-2))of13,324 h.When compared with the SC-based device,the EQE and lifetime were improved by 15% and 183% due to the compact and ordered QD monolayer that lowered the leakage current.Moreover,white QLEDs with stacked QD monolayers could be obtained at a low voltage of 4 V because LB technique is an organic-solvent-free approach avoiding interlayer mixing and controlling the QD layer thickness precisely.In addition,we successfully fabricated an ultra-homogeneous large-area QD monolayer on a rectangular substrate with a size of 9 cm×5 cm,indicating the promising size scalability of the LB-HL strategy.展开更多
Low-k and high aspect ratio blind through-silicon-vias （TSVs） to be applied in ＂via-last/backside via＂ 3-D integration paradigm were fabricated with polyimide dielectric liners formed by vacuum-assisted spin coati...Low-k and high aspect ratio blind through-silicon-vias （TSVs） to be applied in ＂via-last/backside via＂ 3-D integration paradigm were fabricated with polyimide dielectric liners formed by vacuum-assisted spin coating technique. MIS trench capacitors with diameter of-6 μm and depth of-54 μm were successfully fabricated with polyimide insulator step coverage better than 30%. C-V characteristics and leakage current properties of the MIS trench capacitor were evaluated under thermal treat- ment. Experimental results show that, the minimum capacitance density is around 4.82 nF/cm2, and the leakage current density after 30 cycles of thermal chock tests becomes stable and it is around 30 nA/cm2 under bias voltage of 20 V. It also shows that, the polyimide dielectric liner is with an excellent capability in constraining copper ion diffusion and mobile charges even un- der test temperature as high as 125℃. Finite element analysis results show that TSVs with polyimide dielectric liner are with lower risks in SiO2 interlayer dielectric （ILD） fracture and interfacial delamination along dielectric-silicon interface, thus, higher thermo-mechanical reliability can be expected.展开更多
基金supported by the National Natural Science Foundation of China(62075043)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZZ126)。
文摘Regarding conventional quantum dot lightemitting diodes(QLEDs)fabricated by using the spin-coating(SC)technique,voids and interstitial spaces are inevitable due to unordered quantum dots(QDs)stacking,generating device leakage current under an external bias.In the present study,we fabricated an ultra-homogeneous and highly ordered QD monolayer by adopting the Langmuir-Blodgett(LB)technique.The QD monolayer was transferred as a emissive layer with a horizontal lifting(HL)method to a red QLED,which exhibited high performance with an external quantum efficiency(EQE)of 19.0% and lifetime(T_(95)@100 cd m^(-2))of13,324 h.When compared with the SC-based device,the EQE and lifetime were improved by 15% and 183% due to the compact and ordered QD monolayer that lowered the leakage current.Moreover,white QLEDs with stacked QD monolayers could be obtained at a low voltage of 4 V because LB technique is an organic-solvent-free approach avoiding interlayer mixing and controlling the QD layer thickness precisely.In addition,we successfully fabricated an ultra-homogeneous large-area QD monolayer on a rectangular substrate with a size of 9 cm×5 cm,indicating the promising size scalability of the LB-HL strategy.
基金supported by the National Natural Science Foundation of China(Grant Nos.61404008&61574016)"111"Project of China(Grant No.B14010)
文摘Low-k and high aspect ratio blind through-silicon-vias （TSVs） to be applied in ＂via-last/backside via＂ 3-D integration paradigm were fabricated with polyimide dielectric liners formed by vacuum-assisted spin coating technique. MIS trench capacitors with diameter of-6 μm and depth of-54 μm were successfully fabricated with polyimide insulator step coverage better than 30%. C-V characteristics and leakage current properties of the MIS trench capacitor were evaluated under thermal treat- ment. Experimental results show that, the minimum capacitance density is around 4.82 nF/cm2, and the leakage current density after 30 cycles of thermal chock tests becomes stable and it is around 30 nA/cm2 under bias voltage of 20 V. It also shows that, the polyimide dielectric liner is with an excellent capability in constraining copper ion diffusion and mobile charges even un- der test temperature as high as 125℃. Finite element analysis results show that TSVs with polyimide dielectric liner are with lower risks in SiO2 interlayer dielectric （ILD） fracture and interfacial delamination along dielectric-silicon interface, thus, higher thermo-mechanical reliability can be expected.
