Synthesis of Semicenductor Quantum Dots Phosphors and Their Application for the Elecnoluminescence Devices

1. 成功地合成了尺寸为~ 5nm的CuInS_2量子点。CuInS_2量子点的晶体结构是黄铜矿型还是纤锌矿型，与胺的添加量和添加后的储存时间有关。所得的黄铜矿型和纤锌矿型CuInS_2量子点的光吸收边波长为~ 710nm。黄铜矿型CuInS_2在930nm处有光致发光，而纤锌矿型CuInS_2没有光致发光。在黄铜矿型量子点上观察到的PL波段归因于电子-空穴通过缺陷旋回的复合。通过对起始溶液的进一步研究，通过控制反应时间，成功地合成了尺寸为1.5 ~ 3nm的黄铜矿型CuInS_2量子点。对于CuInSe_2量子点，在200 ~ 300℃的油胺中退火后，发光强度增加，发光波长蓝移。发光特性的变化与量子点晶体结晶度的增加有关。通过在CuInS_2量子点上覆盖ZnS薄层，在光学吸收边缘附近出现了新的PL带。PL波段可能是由激子复合引起的。在本实验中，使用的量子点尺寸为~ 5nm。在2 ~ 3nm大小的量子点上包覆ZnS，可以实现蓝色发光。以ZnS-CuInS_2合金的量子点碰撞溶液为起始溶液，通过电喷涂在玻璃基板上成功地制备了具有明显发光特性的量子点薄膜。我们还制作了玻璃/ITO/Al_2O_3/QDs-film/Al_2O_3/Al等多层el器件结构。然而，我们没有观察到任何电致发光。

1. Synthesis of quantum dots (QDs)CuInS_2 quantum dots with 〜5nm in size were successfully synthesized. The crystal structure of the CuInS_2 QDs, the chalcopyrite-type or the wurtzite-type, was dependent on the amount of the amines and the storage time after addition of amines. The optical absorption edges of the chalcopyrite- and wurtzite-types CuInS_2 QDs obtained were 〜710nm in wavelength. For the chalcopyrite-type CuInS_2, photoluminescence (PL) band at 930nm was observed, and no PL band was observed for the wurtzite-type CuInS_2. The PL band observed for the chalcopyrite-type QDs was attributed to the electron-hole recombination via defect revels. As a result of the further study of the starting solution, we successfully synthesized chalcopyrite-type CuInS_2 QDs with 1.5〜3nm sizes by controlling of the reaction time. For the CuInSe_2 QDs, the increase in PL intensity and the blue shift of the PL wavelength were observed by annealing in oleylamine at 200〜300℃. The changes in the PL properties were related to the increase in the crystallinity of the QDs.2. Improving the PL propertiesThe PL band near optical absorption edge was newly appeared by overcoating of the CuInS_2 QDs by ZnS thin layer. The PL band may be attributable to the exciton recombination. In this experiment, the QDs used was 〜5nm in size. When the QDs with 2〜3nm in size are overcoated by ZnS, the blue PL may be realized.3. Fabrication of the QDs thin films and electroluminescence devicesBy using the ZnS-CuInS_2 alloyed QDs collidal solution as a starting solution, the QDs thin film on the glass substrate, which showed significant PL, was successfully fabricated by electro-spraying. We also fabricated the multilayered EL-device structure, such as glass/ITO/Al_2O_3/QDs-film/Al_2O_3/Al. However, we could not observe any electroluminescence from the device.