Improving performances of ITO/GaP contact on AlGaInP light-emitting diodes

In this paper AlGaInP light emitting diodes with different types of electrodes:Au/Zn/Au-ITO Au/Ti-ITO Au/Ge/Ni-ITO and Au-ITO are fabricated. The photoelectricity properties of those LEDs are studied. The results show that the Au/Zn/Au electrode greatly improves the performance of LEDs compared with the other electrodes. Because the Au/Zn/Au electrode not only forms a good Ohmic contact with indium tin oxide (ITO), but also reduces the specific contact resistances between ITO and GaP, which are 1.273×10-6 ·cm2 and 1.743×10-3 ·cm2 between Au/Zn/Au-ITO and ITO-GaP respectively. Furthermore, the textured Zn/Au-ITO/Zn electrode is designed to improve the performances of LEDs, reduce the forward-voltage of the LED from 1.93 to 1.88 V, and increase the luminous intensity of the LEDs from 126 to 134 mcd when driven at 20 mA.     

离子色谱-串联质谱法测定水中痕量苦味酸

<正>苦味酸即2,4,6-三硝基苯酚,被广泛应用于炸药、染料和皮革等工业生产及医学中的收敛剂和杀菌剂的制备。受硝基吸电子效应的影响,苦味酸有很强的酸性,其可经过呼吸道、消化道和皮肤被人体吸收,引起支气管炎和接触性皮炎等。人体长期吸收苦味酸可导致末梢神经炎,肝、肾功能受损等,严重危害人类健康。因此,我国《地表水环境质量标准》(GB 3838-2002)中将苦味酸作为地表水源的一个常规监测指标。