Facile and One-step Processible CdSe/ZnS Quantum Dots and Pentacene-based Nonvolatile Memory Device

• Published in: Journal of semiconductor technology and science 2018, 18(2), 80, pp.180-186
• Main Authors: Kim, Sae-Wan, Jung, In-Su, Kang, Byoung-Ho, Kwon, Jin-Beom, Lee, Jae-Sung, Lee, Sang-Won, Kim, Ok-Sik, Kim, Ju-Seong, Bae, Jin-Hyuk, Kang, Shin-Won
• Format: Article
• Language: English
• Subjects: 전기공학
• ISSN: 1598-1657; 2233-4866
• DOI: 10.5573/JSTS.2018.18.2.180

In this study, we propose an organic memory device using CdSe/ZnS quantum dots (QDs) and a pentacene blending solution as a charge storage layer with a one-step process. The QDs were localized without any tunneling insulators and were used as hole-trapping sites. Moreover, the QDs and pentacene blending solution formed a type II junction, assisting in the facilitation of energy band bending. The band bending inhibited the back-injection of the holes trapped in the CdSe (core of QDs) into an electrode, thereby developing a hysteretic I-V response during device operation. The synthesized QDs had a photo-luminance peak at 535 nm (Green QDs). The fabricated memory device had a structure of and exhibited current differences (approximately 300 times the ON/OFF ratio) at 0.5 V. The device was fabricated using the spin-coating method. The write voltage was approximately 2.5 V. The erasing process was performed by applying a voltage of approximately −4 V. In addition, the stored charge retained its initial value even after 150 h and the write voltage was maintained after 200 write/erase cycles; the long retention time and high durability will be advantageous for future applications of nonvolatile memory. KCI Citation Count: 2