We improve the performance of organic light-emitting diodes （OLEDs） with both a MoO3 hole injection layer （HIL） and a MoO3 doped hole transport layer （HTL）, and present a systematical and comparative investigati...We improve the performance of organic light-emitting diodes （OLEDs） with both a MoO3 hole injection layer （HIL） and a MoO3 doped hole transport layer （HTL）, and present a systematical and comparative investigation on these devices. Compared with OLEDs with only MoO3 HIL or MoO3 doped HTL, OLEDs with both MoO3 HIL and MoO3 doped HTL show superior performance in driving voltage, power efficiency, and stability. Based on the typical NPB/Alq3 heterojunction structure, OLEDs with both MoO3 HIL and MoO3 doped HTL show a driving voltage of 5.4 V and a power efficiency of 1.41 lm/W for 1000 cd/m2, and a lifetime of around 0. 88 h with an initial luminance of 5268 cd/m2 under a constant current of 190 mA/cm2 operation in air without encapsulation. While OLEDs with only MoO3 HIL or MoO3 doped HTL show higher driving voltages of 6.4 V or 5.8 V and lower power efficiencies of 1.201m/W or 1.341m/W for 1000cd/m2, and a shorter lifetime of 0.33 or 0.60h with an initial luminance of around 5122 or 5300cd/m2 under a constant current of 200 or 216mA/cm2 operation. Our results demonstrate clearly that using both MoO3 HIL and MoO3 doped HTL is a simple and effective approach to simultaneoasly improve both the hole injection and transport efficiency, resulting from the lowered energy barrier at the anode interface and the increased hole carrier density in MoO3 doped HTL.展开更多
Free gold and gold wrapped in sulfides are considered as the object of gold floatation. However,floatation of free gold exhibits more variables in practice.In this study, improving gold recovery of a Pb-Zn sulfide ore...Free gold and gold wrapped in sulfides are considered as the object of gold floatation. However,floatation of free gold exhibits more variables in practice.In this study, improving gold recovery of a Pb-Zn sulfide ore from Yunnan Province, China, was investigated. The results show that free gold and auriferous sulfides account for 94.99 % of total gold. Without adding organic acid in floatation, only 82 % recovery of gold could be obtained.Gold recovery in Au/Pb concentrates increases by 9.29 %with oxalate added and by 7.35 % with citric acid added,respectively, while performances of lead and arsenic nearly keep a constant. A possible reason is that free gold is of wonderful selectivity against pyrite with organic activators.A new method to enhance gold recovery is proposed.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11274402the National Basic Research Program of China under Grant No 2012CB933704+1 种基金the Natural Science Foundation of Guangdong Province under Grant No S2012020011003the Program for Changjiang Scholars and Innovative Research Team in University under Grant No IRT13042
文摘We improve the performance of organic light-emitting diodes （OLEDs） with both a MoO3 hole injection layer （HIL） and a MoO3 doped hole transport layer （HTL）, and present a systematical and comparative investigation on these devices. Compared with OLEDs with only MoO3 HIL or MoO3 doped HTL, OLEDs with both MoO3 HIL and MoO3 doped HTL show superior performance in driving voltage, power efficiency, and stability. Based on the typical NPB/Alq3 heterojunction structure, OLEDs with both MoO3 HIL and MoO3 doped HTL show a driving voltage of 5.4 V and a power efficiency of 1.41 lm/W for 1000 cd/m2, and a lifetime of around 0. 88 h with an initial luminance of 5268 cd/m2 under a constant current of 190 mA/cm2 operation in air without encapsulation. While OLEDs with only MoO3 HIL or MoO3 doped HTL show higher driving voltages of 6.4 V or 5.8 V and lower power efficiencies of 1.201m/W or 1.341m/W for 1000cd/m2, and a shorter lifetime of 0.33 or 0.60h with an initial luminance of around 5122 or 5300cd/m2 under a constant current of 200 or 216mA/cm2 operation. Our results demonstrate clearly that using both MoO3 HIL and MoO3 doped HTL is a simple and effective approach to simultaneoasly improve both the hole injection and transport efficiency, resulting from the lowered energy barrier at the anode interface and the increased hole carrier density in MoO3 doped HTL.
基金financially supported by the National Natural Science Foundation of China(No.51374247)
文摘Free gold and gold wrapped in sulfides are considered as the object of gold floatation. However,floatation of free gold exhibits more variables in practice.In this study, improving gold recovery of a Pb-Zn sulfide ore from Yunnan Province, China, was investigated. The results show that free gold and auriferous sulfides account for 94.99 % of total gold. Without adding organic acid in floatation, only 82 % recovery of gold could be obtained.Gold recovery in Au/Pb concentrates increases by 9.29 %with oxalate added and by 7.35 % with citric acid added,respectively, while performances of lead and arsenic nearly keep a constant. A possible reason is that free gold is of wonderful selectivity against pyrite with organic activators.A new method to enhance gold recovery is proposed.
