Gas-mediated liquid metal printing toward large-scale 2D semiconductors and ultraviolet photodetector

Abstract

A gas-mediated fabrication of centimeter-scale two-dimensional (2D) semiconductors and ultraviolet photodetector by a liquid metal-based printing was reported. Various large-scale 2D materials (Ga2O3, In2O3, SnO) were demonstrated to be directly printed at ambient air on different substrates. Such printing represents a generic, fast, clean, and scalable technique to quickly manufacture 2D semiconductors. The electrical properties were explored to quantify the printed 2D films, which were somewhat deficient in previous studies. In particular, to explore and facilitate the advantages of this 2D semiconductor in functional electronic applications, strategies for realizing fully printed Ga2O3/Si heterojunction photodetector via low-temperature and low-cost processes were developed. The device exhibits excellent sensibility and rapid photoresponse times. This work offers feasible way to develop high-performance ultraviolet photodetector for mass production. It also suggests a promising direction for making large-scale 2D photoelectronic and electronic systems and is expected to be extensively useful in the coming time.

Applications of liquid metals in nanotechnology

“…60,61 Other stamping, brushing, squeegeeing and high shear methods were devised for oxide skin collection from LM melts. [62][63][64][65][66][67][68] The ultra-smooth and reactive surface of LMs can also be used for templating 2D materials. In contrast to solid metals, LMs possess a dynamic electrical double layer (EDL).…”

High‐Performance Harsh‐Environment‐Resistant GaOX Solar‐Blind Photodetectors via Defect and Doping Engineering

“…Advanced SBPDs based on wide bandgap (WBG) materials, such as MgZnO, [8] AlGaN, [9,10] diamond, [11] and Ga 2 O 3 , [12] are believed as subversive substitutes of Si-based SBPDs. Among the various WBG materials, Ga 2 O 3 is the most desirable candidate for SBPDs applications based on the facts that, i) its ultra-wide bandgap (4.5-4.9 eV) corresponds to the solar-blind region directly without the necessity of bandgap modulation by doping or alloying process; [13] ii) its high absorption coefficient for high-energy UV photons benefits outstanding sensitivity in solar-blind region; [14] iii) it balances high solar-bind response and material workability; [15] iv) its large-size bulk single crystals can be put into mass production by low-cost melt-grown methods; [16] and most importantly, v) it has high structural stability toward temperature, radiation, and electric field for harsh-environment application. [17] High-quality Ga 2 O 3 material, including single-crystal substrates, nanostructures, and epitaxial films, [14,18,19] facilitate sharp junction interface, such as P-N heterojunction, [20] N-N heterojunction, [21] phase junction, [22] and Schottky junction, [23] to improve the solar-blind response performance.…”

Liquid metals: an ideal platform for the synthesis of two-dimensional materials

“…3a). 40,44,69 However, one should always be aware of the potential for introducing undesired cracks into the synthesised 2D sheets, which has been observed in previous work. 40 Brushing, on the other hand, is carried out by placing the substrate with fully oxidised liquid metal on it facing down, followed by gently brushing on to another substrate.…”

“…Two-dimensional (2D) metal oxides can be isolated through various liquid metal-based techniques, including printing (touch, 4 squeeze, 6,37 or blade print [40][41][42][43][44][45] techniques), liquid phase growth and exfoliation (including sonication 46 and bubbling 4,47,48 methods), and surface templated growth of materials on liquid metal surfaces. 49,50 The liquid metal printing processes may also be used to assist the synthesis of heterostructures which will be discussed later in this review.…”

“…Blade coating is another alternative to the touch-and squeeze-printing techniques. 40,44 Several studies have reported different ways to perform this method, including brushing, 41 tape printing, 42,43 and roll transfer. 45 Nevertheless, they share a similarity in concept whereby a liquid metal is being moved across the substrate and leaves behind an oxide skin which is only weakly attached to the parent liquid metal.…”