Fast Photoresponse and Long Lifetime UV Photodetectors and Field Emitters Based on ZnO/Ultrananocrystalline Diamond Films. Issue 45 (18th September 2015)

• Record Type: Journal Article
• Authors: Saravanan, Adhimoorthy; Huang, Bohr‐Ran; Lin, Jun‐Cheng; Keiser, Gerd; Lin, I‐Nan
• Is Part Of: Chemistry. Volume 21:Issue 45(2015)
• Page Start: 16017
• Page End: 16026
• Publication Date: 2015-09-18
• Subjects: diamond films -- lithography -- photochemistry -- nanostructures -- UV field emitters -- UV photodetectors; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201501538
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: We have designed photodetectors and UV field emitters based on a combination of ZnO nanowires/nanorods (ZNRs) and bilayer diamond films in a metal–semiconductor–metal (MSM) structure. The ZNRs were fabricated on different diamond films and systematic investigations showed an ultra‐high photoconductive response from ZNRs prepared on ultrananocrystalline diamond (UNCD) operating at a lower voltage of 2 V. We found that the ZNRs/UNCD photodetector (PD) has improved field emission properties and a reduced turn‐on field of 2.9 V μm −1 with the highest electron field emission (EFE) by simply illuminating the sample with ultraviolet (UV) light. The photoresponse ( I photo / I dark ) behavior of the ZNRs/UNCD PD exhibits a much higher photoresponse (912) than bare ZNRs (229), ZNRs/nanocrystalline diamond (NCD; 518), and ZNRs/microcrystalline diamond (MCD; 325) under illumination at λ =365 nm. A photodetector with UNCD films offers superior stability and a longer lifetime compared with carbon materials and bare ZNRs. The lifetime stability of the ZNRs/UNCD‐based device is about 410 min, which is markedly superior to devices that use bare ZNRs (92 min). The ZNRs/UNCD PD possesses excellent photoresponse properties with improved lifetime and stability; in addition, ZNRs/UNCD‐based UV emitters have great potential for applications such as cathodes in flat‐panel displays and microplasma display devices. Abstract : Good as diamond : Photoresponse and UV field emitters with good lifetimes and stability were obtained by using ZnO nanowires/nanorods (ZNRs) and ZNRs/ultrananocrystalline diamond (UNCD; see figure).