Universal growth of ultra-thin III–V semiconductor single crystals

Abstract

Ultra-thin III–V semiconductors, which exhibit intriguing characteristics, such as two-dimensional (2D) electron gas, enhanced electron–hole interaction strength, and strongly polarized light emission, have always been anticipated in future electronics. However, their inherent strong covalent bonding in three dimensions hinders the layer-by-layer exfoliation, and even worse, impedes the 2D anisotropic growth. The synthesis of desirable ultra-thin III–V semiconductors is hence still in its infancy. Here we report the growth of a majority of ultra-thin III–V single crystals, ranging from ultra-narrow to wide bandgap semiconductors, through enhancing the interfacial interaction between the III–V crystals and the growth substrates to proceed the 2D layer-by-layer growth mode. The resultant ultra-thin single crystals exhibit fascinating properties of phonon frequency variation, bandgap shift, and giant second harmonic generation. Our strategy can provide an inspiration for synthesizing unexpected ultra-thin non-layered systems and also drive exploration of III–V semiconductor-based electronics.

Recent Advances in 2D Rare Earth Materials

“…Since the discovery of graphene in 2004, more and more 2D materials such as transition metal dichalcogenides (TMDs), [1][2][3] III-V group, [4][5][6][7] III-VI group, [8][9][10][11][12][13] and IV-VI group have been reported. [14][15][16][17][18][19][20][21] The promising properties of 2D materials include attractive carrier mobility, peculiar excitonic, widely adjustable bandgaps, and light-matter interaction properties.…”

Infinite possibilities of ultrathin III-V semiconductors: Starting from synthesis

“…Taking InP as an example, the polarization-resolved SHG suggested a 6-fold anisotropic behavior of 2D InP single crystal. Moreover, SHG can be employed to study the crystal quality and stacking modes ( Chen et al., 2020 ; Kumar et al., 2013 ; Li et al, 2018 ).…”

Device performance and strain effect of sub-5 nm monolayer InP transistors

“…Among these III–V semiconductors, indium phosphide (InP) is one of the extensively studied materials. 9,11–13 The electron mobility of bulk InP is up to 5900 cm 2 V −1 s −1 , which is more than three times larger than that of bulk Si (1450 cm 2 V −1 s −1 ). 14 Besides, bulk InP has a higher electron saturation velocity than bulk Si experimentally (2.5 × 10 7 and 1 × 10 7 cm s −1 for InP and Si, respectively), and the simulated saturated drain current of the bulk InP-based field-effect transistor (FET) is about twice that of the bulk Si-based FET at the same gate length ( L g = 45 nm) and gate voltage.…”

“…Experimentally, InP film has been successfully thinned down to 6.3 nm by using the layer-by-layer growth method. 12 Continuing to reduce the thickness of the UTInP, the gate controllability will be further improved. This can be illustrated by the natural length λ , which describes the penetrating distance of the electrical field from the source/drain to the channel.…”

“…A theoretical study showed that the ML InP is possibly synthesized with an appropriate substrate (such as AuIn 2 ) based on the layer-by-layer growth method. 12 Experimentally, Si FETs with sub-10 nm L g have been successfully fabricated. 21–23 However, to our knowledge, investigation of a sub-10 nm L g UTInPOI FET is still absent.…”