Rodríguez-Mas Fernando, Ferrer Juan Carlos, Alonso José Luis, Fernández de Ávila Susana, Valiente David
Communications Engineering Department, Universidad Miguel Hernández, 03202 Elche, Spain.
Nanomaterials (Basel). 2021 Mar 5;11(3):645. doi: 10.3390/nano11030645.
In this study, poly(9-vinylcarbazole) (PVK)-based LEDs doped with reduced graphene oxide (rGO) and cadmium sulphide (CdS) nanocrystals were fabricated by spin-coating. The hybrid LED structure was a layer sequence of glass/indium tin oxide (ITO)/PEDOT:PSS|rGO/PVK/Al. rGO was included in the poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) layer due to its energy bands being close to PEDOT:PSS bands, and the possibility of using water for dispersing both polymer and flakes. Optical properties such as photoluminescence and UV-Vis absorption were not affected by the addition of rGO to the PEDOT:PSS solution. However, PVK-based LEDs with rGO showed increased current density compared to those without rGO in the hole transporting layer. Higher electroluminescence intensities were observed for rGO-enriched LEDs, although the shape of the spectrum was not modified. LEDs including CdS nanocrystals in the poly(9-vinylcarbazole) emissive layer did not show such dependence on the rGO presence. Though the addition of rGO to PEDOT:PSS still produces a slightly higher current density in CdS doped LEDs, this growth is no longer proportional to the rGO load.
在本研究中，通过旋涂法制备了掺杂有还原氧化石墨烯（rGO）和硫化镉（CdS）纳米晶体的基于聚（9-乙烯基咔唑）（PVK）的发光二极管。混合发光二极管结构为玻璃/氧化铟锡（ITO）/聚（3,4-乙撑二氧噻吩）-聚（苯乙烯磺酸盐）（PEDOT:PSS）|rGO/PVK/Al的层序列。rGO包含在PEDOT:PSS层中，因为其能带与PEDOT:PSS能带接近，且有可能使用水来分散聚合物和薄片。向PEDOT:PSS溶液中添加rGO不会影响光致发光和紫外-可见吸收等光学性质。然而，与空穴传输层中不含rGO的PVK基发光二极管相比，含rGO的PVK基发光二极管的电流密度有所增加。对于富含rGO的发光二极管，观察到更高的电致发光强度，尽管光谱形状未改变。在聚（9-乙烯基咔唑）发射层中包含CdS纳米晶体的发光二极管并未表现出对rGO存在的这种依赖性。虽然向PEDOT:PSS中添加rGO在掺杂CdS的发光二极管中仍会产生略高的电流密度，但这种增长不再与rGO负载量成正比。
