MXene‐GaN van der Waals Heterostructures for High‐Speed Self‐Driven Photodetectors and Light‐Emitting Diodes

Abstract

lithium-ion batteries, [12,13] and electromagnetic interference shielding. [14,15] In addition to these above-mentioned applications, the excellent performance of MXenes makes them ideal for the research in MXene-semiconductor devices. [16] To be specific, MXenes colloidal solution can be fabricated into high-quality thin film through simple methods, such as drop casting and spin-coating, [17,18] thus simplifying the fabrication process of the devices. Besides, MXenes thin film possesses high transmittance and low sheet resistance, [19] which benefits their applications in photodetectors and LEDs. Moreover, the work function of MXene is adjustable in a large range from 2.14 to 5.65 eV, [20,21] which allows it to form Schottky junctions with different semiconductor materials, thereby broadening its application situations.So far, van der Waals heterostructures formed by other 2D materials (such as graphene and TMDs) and conventional semiconductor materials have been investigated widely in various fields and exhibits excellent characteristics. [22][23][24] However, van der Waals heterostructures fabricated by MXene and semiconductor materials have rarely been investigated so far and still need further study. Moreover, as an ideal candidate for optoelectronic devices, GaN has been widely used in photodetectors and LEDs. [25][26][27][28] In this work, Ti 3 C 2 T X /(n/p)-GaN van der Waals heterostructures were fabricated and studied. Ultraviolet photoelectron spectroscopy (UPS) confirms that Ti 3 C 2 T X can form Schottky contacts with both n-GaN and p-GaN at room temperature. By taking the advantages of the Ti 3 C 2 T X /(n/p)-GaN Schottky junctions, we fabricated high-speed photodetectors and stable orange LEDs, respectively. Under the illumination of a 365 nm light source with an intensity of 96.9 µW cm −2 , the Ti 3 C 2 T X /n-GaN photodetector shows a short rise time (60 ms) and decay time (20 ms), a high responsivity (44.3 mA W −1 ) and on/off ratio (≈11 300). And the Ti 3 C 2 T X /p-GaN LED device remains stable orange light emission under bias voltage from 4 to 22 V. We believe that this work gives an essential strategy for photodetectors and LEDs by taking the advantages of MXenes. Due to their excellent electrical conductivity, high transmittance, and adjustable work function, 2D transition-metal carbides and nitrides have shown great promise in optoelectronic applications, especially in MXenesemiconductor devices. In this work, Ti 3 C 2 T X /(n/p)-GaN van der Waals heterostructures are fabricated and studied. The Ti 3 C 2 T X /(n/p)-GaN Schottky junctions are confirmed by ultraviolet photoelectron spectroscopy (UPS) with a work function ≈4.2 eV of Ti 3 C 2 T X . Based on the Ti 3 C 2 T X /(n/p)-GaN Schottky junctions, high-speed photodetectors and stable orange light emitting diodes (LEDs) are fabricated. The Ti 3 C 2 T X /n-GaN heterostructure photodetector shows a short rise time (60 ms) and decay time (20 ms), a high responsivity (44.3 mA W −1 ) and on/off ratio (≈11300) under a light source of 365 nm wa...

Patterning of Wafer‐Scale MXene Films for High‐Performance Image Sensor Arrays

“…[39] Our photodetectors fabricated on the same substrate also show good uniformity, which is essential for large-scale integration (Figures S19 and S20, Supporting Information). We compared its detectivity and L-to-D current ratio with previously reported results [33][34][35][36][37][38][39][40][41][42][43][44] and found that it had the ultrahigh detectivity and light-to-dark current ratio (Figure 2e).…”

2D MXene: A Potential Candidate for Photovoltaic Cells? A Critical Review

“…in 2011 reported 2D MXene nanosheets based on transition metal carbide and nitride materials. [ 21 ] These materials have been extensively studied for numerous applications that include sensors, [ 22 , 23 , 24 ] light‐emitting diodes, [ 25 , 26 , 27 ] energy storage, [ 28 , 29 , 30 , 31 , 32 , 33 , 34 ] water purification, [ 35 , 36 , 37 , 38 ] supercapacitors, [ 39 , 40 , 41 , 42 ] photocatalysis, [ 43 , 44 , 45 , 46 ] biomedical, [ 47 , 48 , 49 , 50 , 51 , 52 ] and electromagnetic [ 52 , 53 , 54 , 55 ] applications. MXenes are a unique and unusual combination of early transition metal carbide/nitrides or carbonitrides that are typically synthesized by a top–down selective etching procedure of their parent hexagonal MAX phases.…”

“…[13][14][15][16][17][18][19][20] Among these materials, Gogotsi et al in 2011 reported 2D MXene nanosheets based on transition metal carbide and nitride materials. [21] These materials have been extensively studied for numerous applications that include sensors, [22][23][24] light-emitting diodes, [25][26][27] energy storage, [28][29][30][31][32][33][34] water purification, [35][36][37][38] K. Rasool Qatar Environment and Energy Research Institute Hamad Bin Khalifa University (HBKU) Qatar Foundation 34110, Doha Qatar F. Mateen Department of Chemical and Biochemical Engineering Dongguk University Seoul 04620, Republic of Korea supercapacitors, [39][40][41][42] photocatalysis, [43][44][45][46] biomedical, [47][48][49][50][51][52] and electromagnetic [52][53][54][55] applications. MXenes are a unique and unusual combination of early transition metal carbide/nitrides or carbonitrides that are typically synthesized by a top-down sele...…”

Heteroepitaxial growth and interface band alignment in a large-mismatch CsPbI3/GaN heterojunction

“…10,11 However, the former no doubt increases the complexity of heteroepitaxy and the latter leads to the optical absorption and exciton emission of the GaN-based heterostructures confined in the short-wavelength or ultraviolet region. Hence, the exploitation of new-type GaN-based heterostructures without the limitation of lattice mismatch is strongly desired, 12–14 which is essential for the development of optoelectronic devices with broadband response and tunable charge-carrier dynamics.…”