Thermal Dissipation Annealing for Crystallization of In‐Doped ZnO Films Deposited on Polyethylene Naphthalate Substrate without Substrate Deformation

Abstract

High‐temperature annealing is essential to crystallize sol–gel spin‐coated ZnO films but is a critical disadvantage in manufacturing flexible and transparent electronics, owing to low thermal stability of polymer substrates. Thus, a novel annealing method, named thermal dissipation annealing (TDA), is developed. TDA method can anneal ZnO films without any deformation of polymer substrates. The effects of TDA method are confirmed by annealing ZnO films deposited on glass and polyethylene naphthalate substrates. Moreover, In‐doped ZnO (IZO) films are annealed by TDA method, and the properties of IZO films are investigated. ZnO films annealed by TDA method show graphene‐like nanosheets and exhibit much higher photosensitivity than ZnO films annealed by furnace or infrared (IR) lamp. For IZO films annealed by TDA method, entangled nanosheets begin to unravel with increasing doping concentration, and size of nanosheets significantly decreases at 0.04 at%. The photosensitivity of the IZO films decreases from 21.77 to 2.76 with increasing doping concentration. Therefore, flexible and transparent UV photodetectors based on sol–gel spin‐coated ZnO films can be fabricated through TDA method; however, when ZnO films annealed by TDA method are utilized to UV photodetectors, In dopant is not a suitable material to improve the performance of UV photodetectors.

NIR Laser Integration of Photodetector on 3D Printed Chamber for Colorimetric Biosensing

“…Noted that the response current saturating in a few minutes is usually observed in metal oxide based photodetectors. [59][60][61][62][63] The response speed is not fast, but is sufficient in colorimetric biosensing. Then, in Figure 6c, we plotted the ΔI-equivalent urea concentration relation measured by 515 nm LED as the calibration curve (black curve).…”

Tungsten-Doped ZnO as an Electron Transport Layer for Perovskite Solar Cells: Enhancing Efficiency and Stability

“…It is found that doping significantly reduces trap defects and promotes charge separation, which leads to improved PCE of PSCs. Aluminum (Al), boron (B), indium (In), and gallium (Ga) are among the most commonly used dopants for ZnO. ,,,, For instance, Mahmood et al demonstrated a PSC with a PCE of 17.18% using In-doped ZnO ETL, and Tseng et al improved PSC’s PCE to 17.6% using Al-doped ZnO ETL. , However, Al can oxidize and form aluminum oxide or alumina (Al 2 O 3 ), which can create grain boundaries and defects that limit the PCE of PSCs . On the other hand, dopants such as gallium, magnesium, lithium, and cobalt have been used, but no significant improvement in the PCE of the PSCs has been achieved. − Thus, tungsten (W) is a promising candidate for the development of doped ZnO ETLs, which shows excellent promise for the realization of efficient PSCs due to its low reactivity and similar ionic radius as Zn 2+ (0.074 nm) and W 6+ (0.064 nm). , These properties of ZnO:W eliminate the lattice distortion of the wurtzite structure ZnO.…”

“…35,41 However, Al can oxidize and form aluminum oxide or alumina (Al 2 O 3 ), which can create grain boundaries and defects that limit the PCE of PSCs. 42 On the other hand, dopants such as gallium, magnesium, lithium, and cobalt have been used, but no significant improvement in the PCE of the PSCs has been achieved. 43−46 Thus, tungsten (W) is a promising candidate for the development of doped ZnO ETLs, which shows excellent promise for the realization of efficient PSCs due to its low reactivity and similar ionic radius as Zn 2+ (0.074 nm) and W 6+ (0.064 nm).…”