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

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.

[1]  Byoung-Ho Kang,et al.  Enhanced Charge Transfer of QDs/Polymer Hybrid LED by Interface Controlling , 2013, IEEE Electron Device Letters.

[2]  Jai Singh,et al.  Roles of binding energy and diffusion length of singlet and triplet excitons in organic heterojunction solar cells , 2012 .

[3]  Hongzheng Chen,et al.  High efficient UV-A photodetectors based on monodispersed ligand-capped TiO2 nanocrystals and polyfluorene hybrids , 2010 .

[4]  Vishal Shrotriya,et al.  Absorption spectra modification in poly(3-hexylthiophene):methanofullerene blend thin films , 2005 .

[5]  Pierre Gibart,et al.  High-performance GaN p-n junction photodetectors for solar ultraviolet applications , 1998 .

[6]  Nan Liu,et al.  Förster resonance energy transfer from poly(9-vinyl carbazole) to silicon nanoparticles in their composite films , 2008 .

[7]  Shenggang Yan,et al.  Low-temperature synthesis of ZnO nanoparticles by solid-state pyrolytic reaction , 2002 .

[8]  A. N. Andreev,et al.  UV photodetectors in 6HSiC , 1992 .

[9]  Hongzheng Chen,et al.  Polymer/ZnO hybrid materials for near-UV sensors with wavelength selective response , 2011 .

[10]  Xiaoyan Zeng,et al.  Fabrication of ZnO and its enhancement of charge injection and transport in hybrid organic/inorganic light emitting devices , 2007 .

[11]  Andreas Kornowski,et al.  Self-assembly of ZnO: from nanodots to nanorods. , 2002, Angewandte Chemie.

[12]  Myrtil L. Kahn,et al.  Size‐ and Shape‐Control of Crystalline Zinc Oxide Nanoparticles: A New Organometallic Synthetic Method , 2005 .

[13]  Hongzheng Chen,et al.  Preparation and optoelectronic properties of a novel poly(N‐vinylcarbazole) with covalently bonded titanium dioxide , 2008 .

[14]  S. Im,et al.  Ultraviolet-enhanced photodiode employing n-ZnO/p-Si structure , 2003 .

[15]  S.J. Chang,et al.  GaN metal-semiconductor-metal photodetectors with low-temperature-GaN cap layers and ITO metal contacts , 2003, IEEE Electron Device Letters.

[16]  James C Blakesley,et al.  Solution-processed ultraviolet photodetectors based on colloidal ZnO nanoparticles. , 2008, Nano letters.

[17]  Dongxu Zhao,et al.  High spectrum selectivity organic/inorganic hybrid visible-blind ultraviolet photodetector based on ZnO nanorods , 2010 .

[18]  Byoung-Ho Kang,et al.  Highly efficient hybrid light-emitting device using complex of CdSe/ZnS quantum dots embedded in co-polymer as an active layer. , 2010, Optics express.

[19]  Eric A. Meulenkamp,et al.  Synthesis and Growth of ZnO Nanoparticles , 1998 .

[20]  Chun-Wei Chen,et al.  Near-ultraviolet photodetector based on hybrid polymer/zinc oxide nanorods by low-temperature solution processes , 2008 .

[21]  Qingfeng Dong,et al.  A nanocomposite ultraviolet photodetector based on interfacial trap-controlled charge injection. , 2012, Nature nanotechnology.

[22]  Abhishek Motayed,et al.  Tunable Ultraviolet Photoresponse in Solution-Processed p-n Junction Photodiodes Based on Transition-Metal Oxides. , 2015, ACS applied materials & interfaces.