The Effect of Inorganic/Organic Hybrid Quantum-Well Structure on Efficient White Organic Light Emitting Devices
In this study, the effect of MQW structures adopting inorganic material (sodium fluoride) has been demonstrated. Brightness, current efficiency was significantly enhanced with a NaF/NPB MQW structure being inserted. The admittance spectroscopy was measured to explain the different mechanism of reducing hole between organic/organic inorganic/organic MQW
Study of efficient and stable organic light-emitting diodes with 2-methyl-9,10-di(2-naphthyl)anthracene as hole-transport material by admittance spectroscopy
An organic light-emitting device with enhanced efficiency sby employing 2-methyl-9,10-di(2-naphthyl)anthracene (MADN) as hole-transport material (HTM) has been developed. The admittance spectroscopy studies indicate that using MADN as HTM can reduce the amount of hole carriers injected into the device leading to a well-balanced carrier recombination. The green fluorescent 10-(2-benzothiazolyl)-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H,11H-benzo[l]pyrano-[6,7,8-ij]quinolizin-11-one doped tris(8-quinolinolato)aluminum device achieved a current efficiency of 21.8 cd/A and a power efficiency of 10.4 lm/W at 20 mA/cm2 that are 65% higher than those of the control device. The green-doped device also achieved a long half-decay lifetime of 22 000 h at an initial brightness of 500 cd/m2.
The Analysis on Fire Smoke Exhausting Robot Vibration Based on Wavelet Transform
Belt relaxation, which affects a lot on operation reliability of the fire smoke exhausting robot, is hard to detect. In this paper, a new method for belt relaxation feature recognition based on continuous wavelet transform (CWT) is proposed, and a vibration model which simplified the robot as a 2-dof forced vibration system under harmonic excitation is established. The vibration acceleration signal has been collected using the IEPE sensor and data acquisition card, experimental results verified the accuracy of the vibration model, and weak impact signal caused by the belt relaxation was distinguished, that testify the practicability of the CWT method in belt relaxation feature recognition.