A near-infrared photoinverter based on ZnO and quantum-dots. Issue 41 (27th June 2018)

• Record Type: Journal Article
• Authors: Kim, Byung Jun; Park, Sungho; Cha, Soon Kyu; Han, Il Ki; Kang, Seong Jun
• Is Part Of: RSC advances. Volume 8:Issue 41(2018)
• Page Start: 23421
• Page End: 23425
• Publication Date: 2018-06-27
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c8ra03588a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : A near-infrared photoinverter was fabricated based on ZnO and quantum-dots. We found that the small band gap quantum-dots could absorb low-energy near-infrared photons, generate photo-excited carriers, and inject them into the conduction band of ZnO. Abstract : Near-infrared (NIR) photoswitching transistors have been fabricated using a hybrid structure of zinc oxide (ZnO) and quantum-dots (QDs). The ZnO active layer was prepared using a solution process, while colloidal QDs were inserted between a silicon dioxide (SiO2 ) gate insulator and a ZnO active layer. The small band gap QDs (1.59 eV) were used to absorb low-energy NIR photons, generate photo-excited carriers, and inject them into the conduction band of the ZnO film. The device with the interfacial QDs induced photocurrents upon exposure to 780 nm-wavelength light. The photoresponsivity of the ZnO/QD device was 0.06 mA W −1, while that of the device without QDs was 1.7 × 10 −5 mA W −1, which indicated that the small band gap QDs enabled a photo-induced current when exposed to NIR light. Furthermore, a photoinverter was prepared which was composed of a ZnO/QDs phototransistor and a load resistor. Photoswitching characteristics indicated that the photoinverter was well modulated by a periodic light signal of 780 nm in wavelength. The results demonstrate a useful way to fabricate NIR optoelectronics based on ZnO and QDs.