1Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shannxi Key Lab of Information Photonic Technique, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049 2School of Physical Science and Technology, Lanzhou University, Lanzhou 730000
Abstract：Room-temperature negative differential resistance (NDR) has been observed in different types of organic materials. However, detailed study on the influence of the organic material on NDR performance is still scarce. In this work, room-temperature NDR is observed when CdSe quantum dot (QD) modified ITO is used as the electrode. Furthermore, material dependence of the NDR performance is observed by selecting materials with different charge transporting properties as the active layer, respectively. A peak-to-valley current ratio up to 9 is observed. It is demonstrated that the injection barrier between ITO and the organic active layer plays a decisive role for the device NDR performance. The influence of the aggregation state of CdSe QDs on the NDR performance is also studied, which indicates that the NDR is caused by the resonant tunneling process in the ITO/CdSe QD/organic active layer structure.
2015, Vol. 32 
