Crystallization of ZnO thin films via thermal dissipation annealing method for high-performance UV photodetector with ultrahigh response speed

Abstract

ZnO-based ultraviolet (UV) photodetector can be easily fabricated by using sol–gel spin-coating method, however, the crystallization of amorphous state ZnO thin films is necessary to fabricate high performance UV photodetector. Thus, we devised a thermal dissipation annealing (TDA) method in which the heat transfer to the ZnO thin films can be synchronized with the heat release from the substrate. It was found that sol–gel spin-coated ZnO thin films can be crystallized through the mobility difference of ZnO molecules placed at the surface of ZnO thin films. Also, UV photodetector based on ZnO thin films annealed with the TDA method exhibited faster rise and decay time constant (τr = 35 ms and τd = 73 ms, respectively), a higher on/off current ratio, and reproducible photocurrent characteristics compared to that of the ZnO thin films annealed by using furnace and IR lamp. Therefore, these results indicated that the TDA method is a feasible alternative route for the fabrication of ZnO based high performance optoelectronic devices.

Zinc oxide based gas sensors and their derivatives: a critical review

“…The spin coating method [89][90][91] can employ uniformly maintained thin films on a flat substrate. By optimizing the spray parameters, including the type of surfactant, drop size and flow rate of the solution, the characteristics can be tuned.…”

Combined Effects of Ultraviolet Irradiation and Magnetic Field on the Properties of Dip-coated ZnO thin films

“…ZnO nanostructures have attracted great attention thanks to their unique combination of interesting properties such as non-toxicity, low cost, chemical stability, and good electrical, optical, and piezoelectric properties [2]. These properties make them suitable for use in numerous applications such as light-emitting diodes (LEDs) [3], laser diodes [4], photodetectors [5], UV-photodetector [6,7], sensing devices [8], solar cells [9], solid-state gas sensors [10], field effect transistors [11], chemical and biological sensors [12], and hybrid solar cells [13].…”

Freestanding Silver-Doped Zinc Oxide 2D Crystals Synthesized by a Surface Energy-Controlled Hydrothermal Strategy

“…16,17 The structural stability of ZnO nanosystems under ambient environment and reasonable thermal stability is outstanding. 18,19 Even though UV LED applications, lasing action in nanorods/pencils, etc., have been demonstrated, a large band gap beyond the visible range (∼3.37 eV) in ZnO has been one of the roadblocks, restricting its use in visible-range optoelectronics. 20−22 Doping provides an excellent platform for band-gap engineering in oxide systems 23−25 to overcome these restrictions and acquire extra advantage, and it has been quite a dream to achieve it in the 2D phase.…”

“…Recent developments toward the synthesis of monoelemental 2D sheets (Xenes), such as borophene, phosphorene, stanene, germanene, and metal carbides/nitrides (MXenes) have been in the news lately. − The future of flexible electronic, spintronic, photonic, and optoelectronic chips lies in the tunability of band gap and the flexible nature of active materials; straintronics in 2D materials is an evolving discipline . The photoactivity of 2D transition metal oxides (2DTMOs) and nitrides (2DTMNs) is expected to enable them to play a more prominent role. − Zinc oxide (ZnO) in 3D bulk or nanoscale morphology has been notorious, and its electronic behavior has historically been controlled by defects such as oxygen deficiencies, zinc interstitials, and doping. , The structural stability of ZnO nanosystems under ambient environment and reasonable thermal stability is outstanding. , Even though UV LED applications, lasing action in nanorods/pencils, etc., have been demonstrated, a large band gap beyond the visible range (∼3.37 eV) in ZnO has been one of the roadblocks, restricting its use in visible-range optoelectronics. − Doping provides an excellent platform for band-gap engineering in oxide systems − to overcome these restrictions and acquire extra advantage, and it has been quite a dream to achieve it in the 2D phase. The emergence of the 2D phase of ZnO (2D ZnO) has thus been a game-changing discovery.…”