Sanchez Rafael S, Binetti Enrico, Torre Jose A, Garcia-Belmonte G, Striccoli Marinella, Mora-Sero Ivan
Photovoltaic and Optoelectronic Devices Group, Departament de Física, Universitat Jaume I, 12071 Castelló, Spain.
Nanoscale. 2014 Aug 7;6(15):8551-5. doi: 10.1039/c4nr01975j.
Colloidal semiconductor quantum dots (QDs) are extraordinarily appealing for the development of light emitting devices (LEDs) due to tunable and pure color emission, brightness and solution processability. This last advantage of the QD-LEDs is even more evident in the field of infrared emission where the devices currently used are prepared by high cost epitaxial techniques. Here we show the fabrication of low cost NIR QD-LEDs based on high quantum yield core-shell PbS-CdS QDs and a novel inverted device structure. Devices are produced using SnO2:F (FTO) as the conductive transparent contact, nanostructured TiO2 as the electron transport layer (ETL) and poly(3-hexylthiophene) P3HT as the hole transport layer (HTL). Despite the roughness of this ETL, the obtained external quantum efficiencies (EQEs) are similar to previously reported values, obtained with regular configuration and more expensive ITO substrates. A turn-on voltage as low as the QD band gap (1.47 eV) is achieved for a large area (1.54 cm(2)) and relatively stable QD-LEDs.
胶体半导体量子点（QDs）由于其可调节的纯色发射、亮度和溶液可加工性，在发光器件（LED）的开发中极具吸引力。量子点发光二极管的这一最后优势在红外发射领域更为明显，目前该领域使用的器件是通过高成本的外延技术制备的。在此，我们展示了基于高量子产率的核壳结构硫化铅-硫化镉量子点和新型倒置器件结构制备低成本近红外量子点发光二极管的方法。器件采用二氧化锡：氟（FTO）作为导电透明接触层、纳米结构的二氧化钛作为电子传输层（ETL）以及聚（3-己基噻吩）P3HT作为空穴传输层（HTL）来制造。尽管该电子传输层表面粗糙，但所获得的外量子效率（EQEs）与之前报道的采用常规结构和更昂贵的氧化铟锡（ITO）衬底所获得的值相似。对于大面积（1.54平方厘米）且相对稳定的量子点发光二极管，实现了低至量子点带隙（1.47电子伏特）的开启电压。
