Low Dark-Current, High Current-Gain of PVK/ZnO Nanoparticles Composite-Based UV Photodetector by PN-Heterojunction Control

Sensors

Sang-Won Lee³  Seung-Hwan Cha³  Kyung-Jae Choi²  Byoung-Ho Kang¹  Jae-Sung Lee³  Sae-Wan Kim³  Ju-Seong Kim³  Hyun-Min Jeong³  Sai-Anand Gopalan³  Dae-Hyuk Kwon⁴  Shin-Won Kang³ 

[1] Center for Functional Devices Fusion Platform, Kyungpook National University, 80 Daehakro, Bukgu, 41566 Daegu, Korea;Department of Sensor and Display Engineering, Kyungpook National University, 80 Daehakro, Bukgu, 41566 Daegu, Korea;School of Electronics Engineering, College of IT engineering, Kyungpook National University, 80 Daehakro, Bukgu, 41566 Daegu, Korea;Department of Electronics Engineering, Kyungil University, 50 Gamasil-Gil, Hayang-Eup, Gyeongbuk, 38428 Gyeongsan-Si, Korea;

关键词: UV photodetector;    pn-heterojunction;    hybrid photoactive layer;    ZnO nanoparticles;   

DOI  :  10.3390/s16010074

来源: mdpi

【 摘 要 】

We propose a solution-processable ultraviolet (UV) photodetector with a pn-heterojunction hybrid photoactive layer (HPL) that is composed of poly-n-vinylcarbazole (PVK) as a p-type polymer and ZnO nanoparticles (NPs) as an n-type metal oxide. To observe the effective photo-inducing ability of the UV photodetector, we analyzed the optical and electrical properties of HPL which is controlled by the doping concentration of n-type ZnO NPs in PVK matrix. Additionally, we confirmed that the optical properties of HPL dominantly depend on the ZnO NPs from the UV-vis absorption and the photoluminescence (PL) spectral measurements. This HPL can induce efficient charge transfer in the localized narrow pn-heterojunction domain and increases the photocurrent gain. It is essential that proper doping concentration of n-type ZnO NPs in polymer matrix is obtained to improve the performance of the UV photodetector. When the ZnO NPs are doped with the optimized concentration of 3.4 wt.%, the electrical properties of the photocurrent are significantly increased. The ratio of the photocurrent was approximately 10³ higher than that of the dark current.

【 授权许可】

CC BY   
© 2016 by the authors; licensee MDPI, Basel, Switzerland.